WAEC SSCE - Physics - 2016 (Objective)

Question 1 Report

At a birthday party, the celebrant pops a corked fruit wine. If the cork shoots out of the bottle at an angle of 40^o to the horizontal and travels a horizontal distance of 4.50m in 1.25s. Calculate the initial speed of the cork.

4.2ms^-1

4.7ms^-1 Correct answer

5.6ms^-1

7.1ms^-1

Answer Details

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Motion

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Question 2 Report

Complementary colours are those which

have the same refractive index

have the same wavelength

add-up to produce black light

add-up to produce white light Correct answer

Answer Details

Read lesson note on Refraction Of Light Through Plane And Curved Surfaces (JAMB)

Read lesson note on Properties Of Waves: Reflection, Refraction, Diffraction (WAEC)

Refraction Of Light Through Plane And Curved Surfaces

Properties Of Waves: Reflection, Refraction, Diffraction

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Question 3 Report

Which of the following factors does not affect the e.m.f of a primary cell? Its

size Correct answer

internal resistance

operating temperature

duration of usage

Answer Details

Read lesson note on Electric Cells (JAMB)

Electric Cells

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Question 4 Report

A plank is placed along the path on which a wheel barrow containing sand is pushed at a construction site to prevent it from sticking as illustrated in the diagram given. The large area of the plank prevents the wheel barrow from getting stuck by

increasing the reaction on the ground

increasing the pressure on the ground

decreasing the pressure on the ground Correct answer

decreasing the weight on the ground

Answer Details

The plank helps to prevent the wheelbarrow from getting stuck by decreasing the pressure on the ground. When the wheelbarrow is pushed over sand or soft ground, its weight can cause it to sink into the ground, making it difficult to move. The plank provides a wider surface area for the weight of the wheelbarrow to be distributed over, which reduces the pressure exerted on the ground. This makes it easier for the wheelbarrow to move over the soft ground without sinking in. So, the correct option is "decreasing the pressure on the ground."

Read lesson note on Pressure (JAMB)

Read lesson note on Liquids At Rest (JAMB)

Pressure

Liquids At Rest

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Question 5 Report

A mercury-in-glass thermometer read 4cm at ice point and 29cm at steam point. Calculate the temperature when the mercury level is at 9cm

13^oC

20^oC Correct answer

33^oC

38^oC

Answer Details

To find the temperature when the mercury level is at 9cm, we need to first calculate the length of the mercury column from the ice point to the 9cm mark. The total length of the mercury column from the ice point to the steam point is 29cm - 4cm = 25cm. To find the length of the mercury column from the ice point to the 9cm mark, we can use the proportion: length of mercury column from ice point to 9cm mark / total length of mercury column = temperature at 9cm / temperature range where the temperature range is the difference between the temperatures of the steam point and ice point. Plugging in the values we know, we get: length of mercury column from ice point to 9cm mark / 25cm = (temperature at 9cm - 0^oC) / (100^oC - 0^oC) Simplifying this equation, we get: length of mercury column from ice point to 9cm mark = (temperature at 9cm / 100) x 25cm Now we can solve for the temperature at the 9cm mark by plugging in the given value for the length of the mercury column at the 9cm mark: 9cm - 4cm = (temperature at 9cm / 100) x 25cm Simplifying this equation, we get: temperature at 9cm = 100 x (9cm - 4cm) / 25cm temperature at 9cm = 20^oC Therefore, the temperature when the mercury level is at 9cm is 20^oC.

Read lesson note on Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

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Question 6 Report

The image formed by a concave mirror is real, inverted and magnified, when object is placed

at the focus

at the centre of curvature

beyond the centre of curvature

between the centre of curvature and the focus Correct answer

Answer Details

Read lesson note on Measurements And Units (JAMB)

Measurements And Units

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Question 7 Report

The two person of a body undergoing a uniformly accelerated motion are (10s, 10ms^-1) and (30s, 50ms^-1). On the velocity-time graph pf the body.

0.5ms^-2

2.0ms^-2 Correct answer

10.0ms^-2

40.0ms^-2

Answer Details

Read lesson note on Scalars And Vectors (WAEC)

Read lesson note on Motion (JAMB)

Read lesson note on Equilibrium Of Forces (WAEC)

Scalars And Vectors

Motion

Equilibrium Of Forces

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Question 8 Report

A uniform metre rule is balanced on a fulcrum placed at the 35cm mark by suspending a mass of 120g at the 10cm mark. Calculate the mass of the metre rule.

60g

80g

120g

200g Correct answer

Answer Details

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Question 9 Report

Resonance occurs when one vibrating object causes a second object to vibrate at its own natural

amplitude

speed

frequency Correct answer

intensity

Answer Details

Resonance is a phenomenon that occurs when one object vibrates and causes another object to vibrate at the same frequency. Every object has a natural frequency at which it likes to vibrate. When an object is forced to vibrate at a different frequency, it does not vibrate as strongly. However, if the frequency of the vibration matches the natural frequency of the object, the object will vibrate with a larger amplitude, or strength, which is known as resonance. To illustrate this, think of a swing. If you push a swing at a random time, it will move back and forth, but it won't go very high. However, if you push the swing at the right time, it will go higher and higher with each swing. This is because you are pushing the swing at the same frequency as its natural frequency, causing it to resonate and swing with greater amplitude. In summary, resonance occurs when an object is forced to vibrate at its natural frequency, causing it to vibrate with greater strength or amplitude. The key factor in resonance is the frequency of the vibration, rather than the speed, intensity, or amplitude.

Read lesson note on Equilibrium Of Forces (WAEC)

Equilibrium Of Forces

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Question 10 Report

Which of the following statements is correct about the effect of dissolved salt on the freezing point of water?

the freezing point is lowered Correct answer

the freezing point is increased

there is no change in the freezing point

the change in the freezing point depends on the temperature of the surrounding

Answer Details

When salt is dissolved in water, it lowers the freezing point of water. This is because the salt ions attract some of the water molecules, which makes it harder for the water molecules to come together and form ice crystals. As a result, a lower temperature is needed for water to freeze in the presence of salt than in pure water. This phenomenon is used to de-ice roads and sidewalks during the winter. By spreading salt on icy surfaces, the salt dissolves in the thin layer of water on top of the ice, which lowers the freezing point and causes the ice to melt.

Read lesson note on Quantity Of Heat (JAMB)

Quantity Of Heat

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Question 11 Report

Two different materials, rubbed against each other acquired opposite charges when separated. This is an example of charging by

induction

friction Correct answer

conduction

convection

Answer Details

The process of rubbing two different materials against each other and causing them to acquire opposite charges when separated is an example of charging by friction. When the two materials are rubbed together, electrons are transferred from one material to the other, causing one material to become positively charged and the other to become negatively charged. This is because electrons are negatively charged particles and when they are transferred from one material to the other, they create an imbalance of charges. This process is also known as triboelectric charging, and it is commonly observed in our daily lives, for example, when we rub a balloon on our hair and it becomes attracted to a wall.

Read lesson note on Electrostatics (JAMB)

Electrostatics

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Question 12 Report

The diagram given is used to determine the

boiling point of water

atmospheric pressure

upper fixed point of a thermometer Correct answer

amount of water in the atmosphere

Answer Details

Read lesson note on Temperature And Its Measurement (JAMB)

Read lesson note on Pressure (JAMB)

Temperature And Its Measurement

Pressure

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Question 13 Report

Which of the following statements is not correct about steel and soft iron?

steel is more magnetized than soft iron Correct answer

permanent magnets are usually made of steel

soft iron is more readily magnetized than steel

soft iron more readily loses its magnetism than steel

Answer Details

The statement that is not correct is "steel is more magnetized than soft iron." In general, soft iron is more readily magnetized than steel because it has a higher magnetic permeability. This means that it can be magnetized more easily when exposed to a magnetic field. However, steel can be magnetized to a higher degree than soft iron, meaning that it can hold a stronger magnetic field. This is why permanent magnets are often made of steel, which can retain its magnetic properties over time. The statement that "soft iron more readily loses its magnetism than steel" is generally true. Soft iron has a lower coercivity than steel, which means that it is easier for its magnetic field to be disrupted or demagnetized. Steel, on the other hand, has a higher coercivity, which means that it is more resistant to losing its magnetism. Overall, both steel and soft iron have their unique magnetic properties, and each is better suited for different applications depending on their magnetic needs.

Read lesson note on Magnets And Magnetic Fields (JAMB)

Read lesson note on Gravitational Field (WAEC)

Magnets And Magnetic Fields

Gravitational Field

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Question 14 Report

An aluminium cable of diameter 4 x 10^-3m and resistivity 3.0 x 10^-8\(\omega\)m has a resistance of 21\(\Omega\). Calculate the length of the cable. (\(\pi = 3.14\))

8.0 x 10²m

8.8 x 10³m Correct answer

8.0 x 10⁴m

8.8 x 10⁴m

Answer Details

The resistance of a conductor is given by the formula:

R = ρL/A

where R is resistance, ρ (rho) is resistivity, L is the length of the conductor, and A is the cross-sectional area of the conductor.

We are given the resistance of the cable (R = 21 Ω), its diameter (d = 4 x 10^-3 m), and its resistivity (ρ = 3.0 x 10^-8 Ωm). We can use the diameter to find the cross-sectional area of the cable, using the formula:

A = πd²/4

Substituting the given values:

A = π x (4 x 10^-3)²/4 = 1.26 x 10^-5 m²

Now we can rearrange the formula for resistance to solve for the length of the cable (L):

L = RA/ρ

Substituting the given values:

L = 21 x 1.26 x 10^-5 / 3.0 x 10^-8

Simplifying the expression, we get:

L = 8.82 x 10³ m

Therefore, the length of the cable is 8.82 x 10³ m.

So the correct answer is) 8.8 x 10³ m.

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Capacitors

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Question 15 Report

What determines the polarity at the ends of an electromagnet? The

magnitude of the current passing through the wire

material of the core of the magnet

material of the coil

direction of current in the wire Correct answer

Answer Details

Read lesson note on Electric Field (WAEC)

Read lesson note on Magnetic Field (Part 1) (WAEC)

Electric Field

Magnetic Field (Part 1)

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Question 16 Report

The diagram given, represents the graph of stress against strain for an elastic wire. The point Q on the graph is the

elastic linit

breaking point Correct answer

yield point

proportional limit

Answer Details

Read lesson note on Elasticity (JAMB)

Elasticity

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Question 17 Report

A 10\(\mu\)C charge moves with a velocity of 1.0 x 10⁵ ms^-1 at right angle to a uniform magnetic field of flux density 5.0 x 10^-4T. Calculate the force on the charge

5.0 x 10^-5N

5.0 x 10^-4N Correct answer

5.0 x 10⁵N

5.0 x 10⁶N

Answer Details

The force experienced by a charged particle moving in a magnetic field is given by the formula F = Bqv, where F is the force, B is the magnetic field flux density, q is the charge on the particle, and v is the velocity of the particle. Using the given values, we can calculate the force as: F = Bqv = (5.0 x 10^-4 T)(10^-5 C)(1.0 x 10^5 m/s) = 5.0 x 10^-4 N Therefore, the correct answer is: 5.0 x 10^-4 N.

Read lesson note on Electric Field (WAEC)

Electric Field

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Question 18 Report

Let \(\Delta\)x be the uncertainty in the measurements of position and \(\Delta\)p the uncertainty in measurement of momentum. The uncertainty principle relation is given as

\(\Delta\)x . \(\Delta\)p = h

\(\Delta\)x . \(\Delta\)p \(\leq\) = h

\(\Delta\)x . \(\Delta\)p \(\geq\) = h Correct answer

\(\Delta\)x . \(\Delta\)p > h

Answer Details

The uncertainty principle is a fundamental principle in quantum mechanics that states that it is impossible to precisely determine both the position and momentum of a particle at the same time. The principle is expressed mathematically as: \(\Delta\)x . \(\Delta\)p \(\geq\) h where \(\Delta\)x is the uncertainty in the position measurement and \(\Delta\)p is the uncertainty in the momentum measurement, and h is Planck's constant. This principle implies that the more precisely you know the position of a particle, the less precisely you can know its momentum, and vice versa. In other words, there is a trade-off between the precision of these measurements. The principle also implies that there is a fundamental limit to how precisely we can know both the position and momentum of a particle at the same time. This limit is determined by Planck's constant, which is a fundamental constant of nature. Therefore, it is impossible to make measurements with arbitrary precision in quantum mechanics, and there will always be some uncertainty associated with our measurements. It is worth noting that the uncertainty principle is not a limitation of the experimental apparatus or the measurement technique, but rather a fundamental property of nature. It is a consequence of the wave-particle duality of matter in quantum mechanics.

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Question 19 Report

X-rays and infrared rays are both electromagnetic. Which common property do the waves have? Both waves

are longitudinal

have same frequency

have the same wavelength

travel at the same speed in a vacuum Correct answer

Answer Details

The common property that X-rays and infrared rays share is that they are both electromagnetic waves and travel at the same speed in a vacuum. This means that they both propagate through space without the need for a medium, and they both travel at the speed of light, which is approximately 299,792,458 meters per second. However, X-rays have much higher frequencies and shorter wavelengths than infrared rays, which means they have higher energy and can penetrate through solid objects, while infrared rays have longer wavelengths and are primarily used for heating and sensing purposes.

Read lesson note on Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum (WAEC)

Read lesson note on Light Waves (WAEC)

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

Light Waves

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Question 20 Report

The p.d across a parallel-plate capacitor is 10³V. If the distance between the two plates is 10cm. Calculate the magnitude of the electric field strength between the plates.

1.0 x 10⁴Vm^-1 Correct answer

1.0 x 10⁵Vm^-1

1.5 x 10⁵Vm^-1

2.0 x 10⁵Vm^-1

Answer Details

The electric field strength between the plates of a parallel-plate capacitor is given by: E = V/d Where V is the potential difference across the plates, and d is the distance between the plates. Substituting the given values, we get: E = 10^3/0.1 E = 10^4 V/m Therefore, the magnitude of the electric field strength between the plates is 1.0 x 10^4 V/m. is the correct answer.

Read lesson note on Electrostatics (JAMB)

Electrostatics

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Question 21 Report

A student measures the volume of a liquid using a measuring cylinder. What else needs to be measured by the student in order to determine the density of the liquid?

depth of the liquid in the cylinder

mass of the cylinder

mass of the liquid Correct answer

tempersture of the liquid

Answer Details

To determine the density of a liquid, the student needs to measure the mass of the liquid and the volume it occupies. The volume can be measured using the measuring cylinder, while the mass of the liquid can be measured using a balance. The mass of the cylinder itself is not necessary for determining the density of the liquid, as it does not contribute to the density calculation. The depth of the liquid in the cylinder is also not necessary, as the volume of the liquid can be measured regardless of its depth. However, the temperature of the liquid can affect its density, so it is important to measure the temperature and ensure that it is constant during the measurement.

Read lesson note on Measurements And Units (JAMB)

Measurements And Units

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Question 22 Report

Which of the following substances lowers the surface tension of water?

metal

sand

detergent Correct answer

paper

Answer Details

Detergent lowers the surface tension of water. Surface tension is the property of water that causes it to form droplets and resist external forces that can break those droplets apart. It's due to the cohesive forces between water molecules. However, when a substance is added to water, it can disrupt these cohesive forces, which lowers the surface tension of water. Detergent contains molecules that have both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions. When added to water, the hydrophobic regions of detergent molecules will orient themselves towards the air-water interface, while the hydrophilic regions will interact with the water molecules. This reduces the cohesive forces between water molecules, leading to a decrease in surface tension. Metal, sand, and paper do not have properties that lower surface tension. Metal and sand are insoluble in water and do not interact with water molecules in a way that lowers surface tension. Paper is made of cellulose, a hydrophilic material that does not disrupt cohesive forces between water molecules.

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Read lesson note on Liquids At Rest (JAMB)

Pressure

Liquids At Rest

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Question 23 Report

Which of the following statements correctly defines the boiling point of a liquid? The temperature at which the

saturated vapour pressure equals the atmospheric pressure Correct answer

molecules leaves the liquid at a rate equal to the rate at which they return

molecules leave the liquid at a rate higher than that at which they return

molecules leave the liquid at a rate lower than the rate at which they return

Answer Details

The boiling point of a liquid is the temperature at which its saturated vapor pressure becomes equal to the atmospheric pressure. At this temperature, the molecules of the liquid gain enough energy to overcome the intermolecular forces holding them together and escape into the atmosphere as vapor. As the vapor pressure increases, it eventually reaches the same level as the atmospheric pressure, causing bubbles to form throughout the liquid and resulting in the characteristic boiling behavior. correctly defines the boiling point of a liquid.

Read lesson note on Quantity Of Heat (JAMB)

Quantity Of Heat

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Question 24 Report

A ball is dropped from the top of a tower. Due to air resistance,it reaches terminal velocity. Which of the following statement(s) about its motion is/are correct? i. The acceleration of the ball is zero. ii. The net force on the ball is zero. iii. The velocity of the ball increases.

i only

i and ii only Correct answer

ii and iii only

i, ii and iii

Answer Details

When the ball is initially dropped from the top of the tower, it accelerates due to the force of gravity. However, as it falls, it encounters air resistance. Air resistance is a force that opposes the motion of an object through the air. Eventually, the force of air resistance becomes equal in magnitude to the force of gravity, and the ball stops accelerating. This is known as terminal velocity. At terminal velocity, the acceleration of the ball is zero. This is because the net force on the ball is zero. The force of gravity is balanced by the force of air resistance. Thus, statement (i) and (ii) are correct. However, statement (iii) is incorrect. At terminal velocity, the velocity of the ball does not increase. It remains constant. This is because the net force acting on the ball is zero, and Newton's second law of motion states that the acceleration of an object is directly proportional to the net force acting on it. If the net force is zero, the acceleration is zero, and the velocity remains constant. Therefore, the correct option is (i and ii only).

Read lesson note on Equilibrium Of Forces (WAEC)

Equilibrium Of Forces

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Question 25 Report

An aluminium rod of length 1.8m at 10°C is heated to proceed produce a difference in length of 0.007m. Calculate the temperature to which it is heated. (Linear expansivity of aluminium = 2.3 x 10\(^{-5}\)K\(^{-1}\)

155^oC

160^oC

169^oC

179^oC Correct answer

Answer Details

Read lesson note on Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

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Question 26 Report

An object of volume 400cm³ and 2.5gcm^-3 is suspended from a spring balance with half its volume immersed in water. Determine the reading on the spring balance. (Density of water = 1gcm^-3)

1200g

1000g

800g Correct answer

400g

Answer Details

The reading on the spring balance is 800g. To understand why, we need to consider the principle of buoyancy, which states that an object partially or completely submerged in a fluid experiences an upward force equal to the weight of the fluid displaced by the object. In this case, the object has a volume of 400cm³ and a density of 2.5gcm^-3, which means its weight is: 400cm³ x 2.5gcm^-3 = 1000g When the object is partially submerged in water, it displaces a volume of water equal to half its own volume, or 200cm³. Since the density of water is 1gcm^-3, the weight of this displaced water is: 200cm³ x 1gcm^-3 = 200g According to the principle of buoyancy, the object experiences an upward force equal to the weight of the displaced water, which is 200g. Therefore, the reading on the spring balance will be the weight of the object minus the upward buoyant force: 1000g - 200g = 800g So the reading on the spring balance is 800g.

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Question 27 Report

The distance between two successive trough of a wave is 0.4m. If the frequency of the source is 825Hz, Calculate the speed of the wave

165.0 ms^-1

330.0ms^-1 Correct answer

41.5ms^-1

85.0ms^-1

Answer Details

Read lesson note on Types Of Waves (WAEC)

Types Of Waves

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Question 28 Report

The continuous stirring in the method of mixtures to determine the specific thermal capacity of a substance ensures

continuous dissipation of heat to the room

uniform distribution of thermal energy to all parts of the mixture Correct answer

that the thermal energy is confined to the mixture

that there is rapid heat exchange

Answer Details

Read lesson note on Heat Transfer (JAMB)

Read lesson note on Electrical Energy And Power (JAMB)

Read lesson note on Equilibrium Of Forces (JAMB)

Heat Transfer

Electrical Energy And Power

Equilibrium Of Forces

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Question 29 Report

When a body is thrown vertically upwards, its velocity at the maximum height is

maximium

zero Correct answer

double its initial value

half its initial value

Answer Details

When a body is thrown vertically upwards, its velocity at the maximum height is zero. This is because when the body is thrown upwards, it gains potential energy due to its height from the ground. As the body moves higher, its potential energy increases, but its kinetic energy decreases, which means its speed decreases. When the body reaches its maximum height, all of its kinetic energy is converted into potential energy, and the velocity becomes zero for a moment. Then the body starts to fall back down towards the ground, and as it falls, its potential energy decreases, but its kinetic energy increases, which means its speed increases. Therefore, the velocity at the maximum height is zero, and it is also the moment when the direction of the velocity changes from upward to downward.

Read lesson note on Rectilinear Acceleration (WAEC)

Read lesson note on Motion (JAMB)

Rectilinear Acceleration

Motion

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Question 30 Report

Two different materials, rubbed against each other acquired opposite charges when separated. This is an example of charging by

induction

friction Correct answer

conduction

convection

Answer Details

This is an example of charging by friction. When two different materials are rubbed against each other, their surfaces may exchange electrons. Electrons are negatively charged particles that can move from one material to another during friction. As a result, one material may lose electrons and become positively charged while the other material gains electrons and becomes negatively charged. This is why the two materials acquire opposite charges when separated. This process is known as triboelectric charging, which is the scientific term for charging by friction.

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Question 31 Report

How many beta particle(s) are emitted in the radioactive decay of \(^{198}_{79}Au \leftarrow ^{198}_{80}Hg\)?

1 Correct answer

Answer Details

In the given radioactive decay equation, beta decay occurs when a neutron in the nucleus of Hg-198 is converted into a proton, causing the atomic number to increase by one and the atomic mass to remain the same. In beta decay, a high-energy electron is emitted from the nucleus.

The equation for beta decay is:

n → p + e- + anti-νe

where n represents a neutron, p represents a proton, e- represents an electron, and anti-νe represents an antineutrino.

Therefore, in the given decay equation, one beta particle (electron) will be emitted as a neutron is converted to a proton.

Hence, the answer is 1.

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Question 32 Report

Given that v, f and \(\lambda\) are the velocity, frequency and wavelength of a wave respectively. Which of the following equations is correct?

v = f²\(\lambda\)

f = \(\frac{v}{\lambda}\) Correct answer

f = \(\frac{v}{\lambda^2}\)

\(\lambda = \frac{f}{v^2}\)

Answer Details

The correct equation is: f = \(\frac{v}{\lambda}\). This equation represents the relationship between the frequency, wavelength, and velocity of a wave. It states that the frequency of a wave is equal to the velocity of the wave divided by its wavelength. In other words, if you know the velocity and wavelength of a wave, you can calculate its frequency using this equation. Alternatively, if you know the frequency and velocity of a wave, you can calculate its wavelength using the same equation. The other equations given in the options are not correct. The first equation v = f²\(\lambda\) implies that the velocity of a wave is proportional to the square of its frequency and wavelength, which is not true. The second equation f = \(\frac{v}{\lambda^2}\) implies that the frequency of a wave is inversely proportional to the square of its wavelength, which is also not true. The last equation \(\lambda = \frac{f}{v^2}\) implies that the wavelength of a wave is inversely proportional to the square of its frequency and velocity, which again is not true.

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Question 33 Report

The phenomenon by which two light atomic nuclear combine to form a heavy nuclide with the release of energy is known as

radioactivity

nuclear fusion Correct answer

nuclear fission

chain reaction

Answer Details

The phenomenon by which two light atomic nuclei combine to form a heavier nucleus with the release of energy is called nuclear fusion. In nuclear fusion, the nuclei of two atoms come together to form a single, heavier nucleus. This process releases a large amount of energy in the form of light and heat. Nuclear fusion is the process that powers the sun and other stars. Scientists are trying to harness this process as a source of energy on Earth, but it is very difficult to achieve because it requires very high temperatures and pressures to overcome the repulsion between the positively charged nuclei.

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Structure Of The Nucleus

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Question 34 Report

A pressurized perfume bottle is left on the window pane of a room. What happens to he gas molecules of the perfume on a sunny day? They

expand

collide less often

move more rapidly Correct answer

contract

Answer Details

On a sunny day, the gas molecules of the perfume inside a pressurized bottle left on a window pane will move more rapidly. This is because the increase in temperature from the sun's heat will cause the gas molecules to gain kinetic energy, which in turn increases their speed. As a result, they will collide more frequently with each other and with the walls of the bottle, exerting a greater pressure. However, the expansion of the gas molecules will be limited by the container's pressure and volume. Therefore, the perfume bottle will not expand or contract. The only observable change will be that the gas molecules inside the bottle will move more rapidly.

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Question 35 Report

The dimensions of momentum are

MLT

ML^-1T^-1

MLT^-1 Correct answer

ML^-1T

Answer Details

The dimensions of momentum are MLT^-1. Momentum is a physical quantity that measures the amount of motion an object has. It is defined as the product of an object's mass and velocity. Mass is a measure of the amount of matter in an object, while velocity is a measure of the speed and direction of motion of the object. The dimension of mass is M (in kilograms), the dimension of velocity is LT^-1 (in meters per second), and the dimension of momentum is the product of mass and velocity, which is MLT^-1. Therefore, the dimension of momentum is MLT^-1.

Read lesson note on Fundamental And Derived Quantities And Units (WAEC)

Fundamental And Derived Quantities And Units

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Question 36 Report

The electricity meters in houses measure energy unit consumed in

kilowatt-hour Correct answer

volt

ampere

coulomb

Answer Details

Electricity meters in houses measure the amount of energy consumed by electrical appliances in a unit called "kilowatt-hour" (kWh). A kilowatt-hour is a measure of energy that is equivalent to using one kilowatt (1,000 watts) of power for one hour. This unit of measurement is used because it takes into account both the amount of power being used (in kilowatts) and the duration of its use (in hours). In contrast, volts measure the electrical potential difference between two points, amperes measure the current flowing through a circuit, and coulombs measure the quantity of electric charge. While these units are important in understanding how electricity works, they are not used to measure the amount of energy consumed by electrical appliances in households.

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Current Electricity

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Question 37 Report

In a p-type semiconductor, the?

number of holes are equal to the number of electrons

electrical resistivity increases

electrons are the majority charge carriers

holes are the majority charge carriers Correct answer

Answer Details

In a p-type semiconductor, holes are the majority charge carriers. Semiconductors are materials that have conductivity between conductors (such as metals) and insulators (such as rubber). In a pure semiconductor, such as silicon or germanium, there are equal numbers of positive (holes) and negative (electrons) charge carriers, and the material is called intrinsic semiconductor. However, by adding impurities to the semiconductor material, we can change its electrical properties. When we add impurities such as boron, which has one less valence electron than the semiconductor material, the boron atom can bond with the semiconductor material leaving a "hole" in the crystal lattice where there should be an electron. These holes are positively charged and can move through the material like a particle. In a p-type semiconductor, the majority of charge carriers are these positively charged holes, while the minority carriers are negatively charged electrons. Therefore, when a voltage is applied, the holes are the ones that move and contribute to electrical conductivity, while the electrons do not move much. As a result, the electrical resistivity of the p-type semiconductor increases because the majority charge carriers (holes) have a lower mobility than electrons.

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Electrostatics

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Question 38 Report

An astronomical telescope has objectives and eye-piece lenses of focal length 3.5m and 5cm respectively. Determine the magnifying power of the telescope when in normal adjustment

70.0 Correct answer

17.5

7.0

0.7

Answer Details

The magnifying power of a telescope is given by the formula: Magnifying power = (focal length of objective lens) / (focal length of eyepiece lens) Substituting the given values, we have: Magnifying power = (3.5 m) / (0.05 m) = 70 Therefore, the magnifying power of the telescope when in normal adjustment is 70.0. The correct option is (a) 70.0.

Read lesson note on Structure Of The Atom (Nigeria Only) (WAEC)

Structure Of The Atom (Nigeria Only)

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Question 39 Report

Total internal reflection. i. is a phenomenon of refraction of light. ii. occurs when light rays travel into a denser medium. iii. occurs when the critical angle is just exceeded. iv. is a phenomenon of reflection of light. Which of the statements above are correct?

i and ii only

i and iii only Correct answer

i, ii and iii only

i, iii and iv only

Answer Details

Read lesson note on Reflection Of Light At Plane And Curved Surfaces (JAMB)

Reflection Of Light At Plane And Curved Surfaces

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Question 40 Report

The diagram given illustrates a force-distance graph for the motion of a wooden block. Determine the work done on the block when moved through a distance of 5m.

15J

100J Correct answer

Answer Details

Read lesson note on Newton’s Laws Of Motion (WAEC)

Read lesson note on Position, Distance And Displacement (WAEC)

Read lesson note on Work, Energy And Power (WAEC)

Newton’s Laws Of Motion

Position, Distance And Displacement

Work, Energy And Power

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Question 41 Report

A man and his friend have masses 70kg and 60kg respectively. If they are seated 1.0m apart, calculate the gravitational force of attraction between them. (G = 6.67 x 10^-11 Nm² kg^-2)

1.59 x 10^-14 N

2.80 x 10^-7 N Correct answer

1.30 x 10^-2 N

6.30 x 10¹³ N

Answer Details

The gravitational force of attraction between two objects can be calculated using the formula F = Gm₁m₂/r², where F is the force of attraction, G is the gravitational constant, m₁ and m₂ are the masses of the two objects, and r is the distance between the centers of the two objects. In this case, the masses of the man and his friend are 70kg and 60kg, respectively, and they are seated 1.0m apart. Therefore, using the above formula, we can calculate the gravitational force of attraction between them as: F = Gm₁m₂/r² = (6.67 x 10^-11 Nm² kg^-2) (70kg) (60kg) / (1.0m)² ≈ 2.80 x 10^-7 N Therefore, the gravitational force of attraction between the man and his friend is approximately 2.80 x 10^-7 N. This force is very small, which is why we do not notice the gravitational force between two ordinary objects in our everyday lives. The reason why we feel the gravitational force of the Earth is because the Earth is a very large object with a very large mass, which produces a significant gravitational force.

Read lesson note on Gravitational Field (JAMB)

Gravitational Field

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Question 42 Report

In the clinical thermometer, the function of the kink is to i. Prevent the back flow of mercury after use. ii. Ensure the back flow of mercury after use. iii. Maintain the thermometric property of mercury. iv. Allow the temperature attained to be read.

i only

i and ii only

i and iv only Correct answer

iii and iv only

Answer Details

Read lesson note on Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

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Question 43 Report

In storing magnets, keepers are used to

reduced self-demagnetization Correct answer

cancel the effect of the earth's magnetic field

protect the magnet from stray electric field

increase the strangth of the magnets

Answer Details

Keepers are used to reduce self-demagnetization of magnets. When a magnet is not in use, it can gradually lose its magnetic strength due to various factors, including temperature changes, vibrations, and exposure to other magnetic fields. This process is called self-demagnetization. A keeper is a piece of ferromagnetic material that is placed across the poles of a magnet to complete its magnetic circuit. This prevents the magnetic field from leaking out and helps maintain the magnet's strength over time. By providing a closed path for the magnetic flux, the keeper ensures that the magnetic energy of the magnet is conserved and not dissipated. Therefore, keepers are useful for storing magnets for prolonged periods to prevent self-demagnetization. They do not cancel the effect of the earth's magnetic field or protect the magnet from stray electric fields, nor do they increase the strength of the magnets.

Read lesson note on Magnets And Magnetic Fields (JAMB)

Magnets And Magnetic Fields

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Question 44 Report

The pair of musical instruments that works on the vibration of air in pipes is

piano and the organ

guitar and the flute

trumpet and the violin

flute and the trumpet Correct answer

Answer Details

The pair of musical instruments that work on the vibration of air in pipes is the flute and the trumpet. The flute is a wind instrument that works by blowing air across a hole, which creates a vibrating column of air inside the instrument's pipe. As the player changes the position of their fingers on the flute's keys, different notes are produced by changing the length of the vibrating column of air. The trumpet, on the other hand, is a brass instrument that works by the player buzzing their lips into a small cup-shaped mouthpiece. This creates a vibrating column of air inside the instrument's long, curved pipe. Like the flute, different notes are produced by changing the length of the vibrating column of air by pressing the instrument's valves. Both the flute and the trumpet use the vibration of air in pipes to produce sound, but they achieve this in slightly different ways. The flute relies on blowing air across a hole, while the trumpet relies on buzzing lips into a mouthpiece.

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Question 45 Report

The diagram given illustrates the waveform of a note produced by vibrations in an air column of length L. If the speed of sound in air is V, derive an expression for the frequency of the notes

\(\frac{V}{L}\)

\(\frac{5VL}{2}\)

\(\frac{5L}{4V}\)

\(\frac{5V}{4L}\) Correct answer

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Read lesson note on Waves (JAMB)

Waves

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Question 46 Report

Two magnets are used to magnetize a soft iron bar PQ as illustrated in the diagram given. The correct polarity at P and Q respectively

S and N

N and N Correct answer

S and S

N and S

Answer Details

Read lesson note on Magnets And Magnetic Fields (JAMB)

Magnets And Magnetic Fields

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Question 47 Report

The mouth piece of a telephone handset converts

electrical energy to sound energy

sound energy to electrical energy Correct answer

sound energy to radiowave

radiowave to sound energy

Answer Details

The mouthpiece of a telephone handset converts sound energy into electrical energy. When you speak into the mouthpiece, your voice creates sound waves. These sound waves cause a small diaphragm in the mouthpiece to vibrate. This vibration is converted into an electrical signal that can be transmitted through the telephone line to the receiver at the other end. In other words, the mouthpiece of a telephone handset works like a microphone, converting sound energy into an electrical signal that can be transmitted through the telephone system.

Read lesson note on Electrostatics (JAMB)

Electrostatics

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