JAMB UTME - Physics - 2018
Ajụjụ 2 Ripọtì
Natural radioactivity consists of the emission of
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Radioactive decay releases different types of energetic emissions. The three most common types of radioactive emissions are alpha particles, beta particles, and gamma rays.
Ajụjụ 3 Ripọtì
Shadows and eclipses result from the
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The rectilinear propagation of light means that light travels in straight lines as a wave. This can be observed in the well-defined shadows formed when an object blocks a light source and through the use of a pinhole camera.
According to Sudipa Sarkar, the formation of shadows with sharp edges demonstrates the rectilinear propagation of light, i.e. The fact that light travels in straight line. When an opaque obstacle is placed between a source of light and a screen, a shadow of the obstacle is formed on the screen. The kind of shadow depends on the size of the source of light. If it is a point source (light from a small hole), the shadow obtained is a region of total darkness, called umbra.
If an extended source of light, e.g. a bulb, is used, the umbra is surrounded by a region of partial darkness, called penumbra. The moon is seen because it reflects the sun's light. An eclipse of the moon (lunar eclipse) occurs when the earth comes between the sun and the moon and prevents some of the light from the sun from reaching the moon. In other words, the earth casts its shadow on the moon. The solar eclipse occurs when the moon comes between the sun and the earth.
According to Sudipa Sarkar, the formation of shadows with sharp edges demonstrates the rectilinear propagation of light, i.e. The fact that light travels in straight line. When an opaque obstacle is placed between a source of light and a screen, a shadow of the obstacle is formed on the screen. The kind of shadow depends on the size of the source of light. If it is a point source (light from a small hole), the shadow obtained is a region of total darkness, called umbra.
If an extended source of light, e.g. a bulb, is used, the umbra is surrounded by a region of partial darkness, called penumbra. The moon is seen because it reflects the sun's light. An eclipse of the moon (lunar eclipse) occurs when the earth comes between the sun and the moon and prevents some of the light from the sun from reaching the moon. In other words, the earth casts its shadow on the moon. The solar eclipse occurs when the moon comes between the sun and the earth.
Ajụjụ 4 Ripọtì
The density of 400cm3 of palm oil was 0.9gcm-3 before frying. If the density of the oil was 0.6gcm-3 after frying, assuming no loss of oil due to spilling, its new volume was?
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The density of a substance is defined as its mass per unit volume. Therefore, the mass of the palm oil before frying was:
Mass = Density x Volume = 0.9 g/cm³ x 400 cm³ = 360 g
After frying, the mass of the palm oil remains the same, but its density changes to 0.6 g/cm³. Therefore, the new volume of the palm oil can be calculated by rearranging the density formula:
Volume = Mass / Density = 360 g / 0.6 g/cm³ = 600 cm³
So the new volume of the palm oil after frying is 600 cm³. is the correct answer.
Ajụjụ 5 Ripọtì
Which of the following best describes the energy changes which take place when a steam engine drives a generator which lights a lamp?
Akọwa Nkọwa
The energy changes that take place when a steam engine drives a generator which lights a lamp can be described as:
Heat energy from burning fuel is used to create steam in the boiler of the steam engine. This steam is then used to drive the turbine, which generates kinetic energy as it spins. The kinetic energy is transferred to the generator, which converts it into electrical energy (electricity). The electricity then flows through the wires to the lamp, where it is converted back into light energy, which is what we see.
Therefore, the correct option would be:
Heat ----> Kinetic ----> Electricity ----> Light
Ajụjụ 6 Ripọtì
In the diagram shown, which of the simple pendulum will resonate with P when set into oscillation?
Ajụjụ 7 Ripọtì
The linear expansivity of brass is \(2 \times 10^{-5}\,\text{C}^{-1}\). If the volume of a piece of brass is 15.00cm at 0°C, what is the volume at 100°C
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The linear expansivity of brass is given as 2 x 10^-5 /°C. This means that for every 1°C increase in temperature, the brass expands by 2 x 10^-5 of its original size.
To find the new volume of the brass at 100°C, we need to take into account the expansion in all three dimensions (length, width, and height). Since the expansivity given is for length only, we need to find the expansivity in all three dimensions by multiplying it by 3.
The expansivity in all three dimensions is:
3 x (2 x 10^-5 /°C) = 6 x 10^-5 /°C
To find the new volume, we can use the formula:
Vf = Vi (1 + αΔT)
where Vf is the final volume, Vi is the initial volume, α is the expansivity in all three dimensions, and ΔT is the change in temperature.
Plugging in the values, we get:
Vf = 15.00 cm3 (1 + (6 x 10^-5 /°C) x (100°C - 0°C))
Vf = 15.09 cm3
Therefore, the volume of the brass at 100°C is 15.09 cm3.
Ajụjụ 8 Ripọtì
The differences observed in solids, liquids and gases may be accounted for by
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The differences observed in solids, liquids, and gases can be accounted for by the spacing and forces acting between the molecules.
In a solid, the molecules are packed closely together, so they have a fixed shape and volume. The intermolecular forces are strong enough to keep the molecules in a fixed position relative to one another.
In a liquid, the molecules are still close together, but they are free to move around each other. The intermolecular forces are weaker than in a solid, so the molecules can slide past one another, giving the liquid its ability to flow and take the shape of its container.
In a gas, the molecules are widely spaced and are in constant motion. The intermolecular forces are very weak, so the molecules are free to move around and fill any available space. Gases have no fixed shape or volume.
So, the differences observed in solids, liquids, and gases can be explained by the spacing and forces acting between the molecules. It's not about their relative masses, melting points, or the different molecules in each of them.
Ajụjụ 10 Ripọtì
A beam of light is incident from air to water at an angle of 300. Find the angle of refraction if the refractive index of water is 4/3
Akọwa Nkọwa
X = 43
r = ?
Shell?s law:. 7 = Sin20Sinr0
Vg = Sin300Sinr0
Sinr0 = 3Sin3004
Sin r0 = 0.375
R o = Sin-1 (0.375)
R o = 22.02 o
R o = 22 o
Shell?s law:. 7 = Sin20Sinr0
Vg = Sin300Sinr0
Sinr0 = 3Sin3004
Sin r0 = 0.375
R o = Sin-1 (0.375)
R o = 22.02 o
R o = 22 o
Ajụjụ 11 Ripọtì
To keep a vehicle moving at a constant speed V requires power P from the engine. The force provided by the engine is
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The force provided by the engine to keep a vehicle moving at a constant speed is proportional to the power (P) required from the engine. This power is proportional to the product of the speed (V) and force (P), so the relationship can be expressed as P = kV, where k is a proportionality constant.
Ajụjụ 12 Ripọtì
The time rate of loss of heat by a body is proportional to the
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The correct answer is "difference in temperature between the body and its surroundings."
When a body is at a higher temperature than its surroundings, it will lose heat to the surroundings until it reaches thermal equilibrium, i.e., until the temperatures of the body and its surroundings are equal. The rate at which the body loses heat is proportional to the temperature difference between the body and its surroundings. This is known as Newton's law of cooling.
The law of cooling applies to a wide range of situations, from the cooling of hot beverages to the cooling of electronic devices. It is important to understand this law because it allows us to predict how long it will take for a body to cool down to a certain temperature, and to design systems that can regulate the temperature of a body, such as heaters or refrigerators.
Ajụjụ 13 Ripọtì
In the diagram given if the atmospheric pressure is 760mm, the pressure in the chamber G Is
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Ajụjụ 14 Ripọtì
Which of the following phenomena cannot be explained by the molecular theory of matter?
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Conduction: the flow of internal energy from a region of higher temperature to lower temperature
Convection: heat transfer due to bulk movement of molecules within fluids
Expansion: the action of becoming larger or more extensive
Convection: heat transfer due to bulk movement of molecules within fluids
Expansion: the action of becoming larger or more extensive
Ajụjụ 15 Ripọtì
In the diagram given the hanging mass m2 is adjusted until m1 is on the verge of sliding. The coefficient of static
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I think the correct option is C (m2m1
). The coefficient of friction is a ratio of two forces and hence g will cancel out.
Ajụjụ 16 Ripọtì
A ball of mass 5.0kg hits a smooth vertical wall normally with a speed of \(2\text{ms}^{-1}\). Determine the magnitude of the resulting impulse
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The magnitude of the resulting impulse can be calculated using the formula impulse = change in momentum. In this scenario, the ball experiences a change in velocity (speed) as it hits the wall. The ball's initial momentum is equal to its mass times its velocity, and its final momentum is zero since it comes to a stop after hitting the wall. The change in momentum is equal to the final momentum minus the initial momentum, which is equal to the negative of the initial momentum.
Since the ball has a mass of 5.0 kg and a velocity of 2 m/s, its initial momentum is 5.0 kg * 2 m/s = 10.0 kg m/s. Therefore, the change in momentum is -10.0 kg m/s and the magnitude of the resulting impulse is 10.0 kg m/s, which is equal to 10.0 Ns.
So, the correct answer is 10.0kgms−1.
Ajụjụ 17 Ripọtì
Calculate the effective capacitance of the circuit in the diagram given
Akọwa Nkọwa
The three 2uf capacitors are in parallel to each other so u add them like this
2uf+2uf+2uf=6uf
So u have three capacitors in series
6uf 2uf and 3uf
They are in series so
1/C= 1/6+1/3=1/2
C=2uf
Then the same thing with the last two capay
1/2+1/2=1uf
Thanks
2uf+2uf+2uf=6uf
So u have three capacitors in series
6uf 2uf and 3uf
They are in series so
1/C= 1/6+1/3=1/2
C=2uf
Then the same thing with the last two capay
1/2+1/2=1uf
Thanks
Ajụjụ 18 Ripọtì
A force of 5N acts at a point Y on a rod XYZ as shown in this diagram. If XYZ is 2m, what is the moment of the force about point X?
Akọwa Nkọwa
To find the moment of the force about point X, we need to first understand what moment is. Moment is the turning effect of a force around a pivot point. It is calculated by multiplying the force by the perpendicular distance between the pivot point and the line of action of the force.
In this case, the force of 5N is acting on the rod at point Y. To find the moment of this force about point X, we need to find the perpendicular distance between point X and the line of action of the force.
From the diagram, we can see that the perpendicular distance between point X and the line of action of the force is 2m (the length of the rod). So, the moment of the force about point X is:
Moment = force x perpendicular distance
= 5N x 2m
= 10Nm
Therefore, the correct answer is: 10Nm.
Ajụjụ 19 Ripọtì
Which of the following is an essential physical property of the wires uses for making fuses ?
Akọwa Nkọwa
The essential physical property of the wire used for making fuses is low melting point. This means that the wire should have a low temperature at which it melts and breaks, interrupting the flow of electrical current. This is important in a fuse because when there is an overload of electrical current, the wire will melt, breaking the circuit and preventing damage to the electrical system.
The other options, low density, low electrical resistivity, and hypothermal conductivity, are not as important for a fuse wire. Low density is the property of a material to be light, and it doesn't necessarily affect the performance of a fuse wire. Low electrical resistivity is the property of a material to have low resistance to the flow of electrical current, and it doesn't necessarily affect the performance of a fuse wire either. Hypothermal conductivity is the property of a material to conduct heat poorly, and it also doesn't necessarily affect the performance of a fuse wire.
Ajụjụ 20 Ripọtì
The energy needed to move a unit positive charge around a complete electric circuit is called the
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The energy needed to move a unit positive charge around a complete electric circuit is called the "electromotive force", also known as "emf". This is because the emf is what drives the flow of electric charge, or current, around the circuit.
Think of it like a battery in a flashlight. The battery provides the emf that drives the flow of electric current through the wires and the light bulb. Without the emf from the battery, the electric charges wouldn't be able to flow and the light wouldn't turn on.
The other answer options, such as electric potential difference and electric energy, are related to the emf but don't specifically refer to the energy needed to move a unit positive charge around a circuit. Kinetic energy, on the other hand, is not related to the movement of electric charges around a circuit at all.
Ajụjụ 21 Ripọtì
A solid weighs 45N and 15N respectively in air and water. Determine the relative density of the solid
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The relative density of a substance is defined as the ratio of its density to the density of a reference substance, usually water at 4 degrees Celsius. In this problem, we can use the principle of buoyancy to determine the density of the solid. When an object is submerged in a fluid, it experiences an upward force called the buoyant force, which is equal to the weight of the fluid displaced by the object. If the object is less dense than the fluid, it will float, and if it is more dense, it will sink. We are given that the solid weighs 15 N in water, which means it displaces 15 N of water. The weight of the water displaced is equal to the buoyant force on the solid, which is equal to the weight of the solid when it is completely submerged in water. Therefore, the weight of the solid when it is completely submerged in water is 15 N. We are also given that the weight of the solid in air is 45 N. The difference between the weight of the solid in air and water is equal to the weight of the water displaced, which is 30 N. This means that the volume of water displaced by the solid is 30/9.8 = 3.06 L (since the density of water is 1000 kg/m^3 or 9.8 N/L). The relative density of the solid is equal to its density divided by the density of water. We can find the density of the solid by dividing its weight in air by its volume: Density of solid = Weight of solid in air / Volume of solid Density of solid = 45 N / (45 N - 15 N) [since weight of displaced water is 15N] Density of solid = 45 N / 30 N Density of solid = 1.5 N/L Therefore, the relative density of the solid is: Relative density = Density of solid / Density of water Relative density = 1.5 N/L / 1000 N/L Relative density = 0.0015 So the answer is 0.33 (rounded to two decimal places).
Ajụjụ 22 Ripọtì
Which of the following has the lowest internal resistance when new?
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Among the given options, the Accumulator has the lowest internal resistance when new.
Internal resistance is the resistance that a battery or cell provides to the flow of electric current within itself. Lower internal resistance means that the battery can supply more current to an external circuit without losing much of its own energy as heat.
An Accumulator, also known as a rechargeable battery, is designed to be charged and discharged multiple times. It has a relatively low internal resistance when new, meaning it can provide a higher current than the other cells listed while wasting less energy internally as heat.
A Leclanche cell and Daniell cell are primary cells, meaning they are designed to be used once and discarded. They have higher internal resistance compared to the accumulator, which limits their ability to supply high currents.
A Torch battery, also known as a dry cell, is also a primary cell and has a higher internal resistance than the accumulator. It is commonly used in small electronic devices and has a longer shelf life than Leclanche and Daniell cells.
In summary, an Accumulator has the lowest internal resistance when new, which makes it an ideal choice for applications requiring high current delivery such as electric vehicles, power tools, and renewable energy systems.
Ajụjụ 23 Ripọtì
Which of the following is the dimension of pressure
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The dimension of pressure is ML-1T-2 Pressure is defined as the force per unit area. This means that pressure is dependent on the force applied and the area over which it is applied. The unit of force is measured in Newtons (N), and the unit of area is measured in square meters (m2). Therefore, the unit of pressure is N/m2, which is also known as Pascals (Pa). To determine the dimension of pressure, we need to break down the units into their fundamental dimensions of mass (M), length (L), and time (T). Force is measured in N, which is kg m/s2. Area is measured in m2, which is L2. Therefore, the dimension of pressure can be calculated as (kg m/s2)/(L2), which simplifies to ML-1T-2.
Ajụjụ 24 Ripọtì
Which of the following statements are TRUE of isotopes?
I. Isotopes of an element have the same chemical properties because they have the same number of electrons
II. Isotopes of elements are normally separated using physical properties
III. Isotopes of an element have the same number of protons in their nuclei
Akọwa Nkọwa
The correct answer is "I and III only".
Isotopes of an element have the same number of protons in their nuclei, meaning they have the same atomic number and are therefore the same element. Because of this, they have the same chemical properties.
However, isotopes of an element have different numbers of neutrons in their nuclei, which means they have different atomic masses. This is why isotopes can be separated using physical properties such as their mass or other characteristics related to their mass.
Ajụjụ 26 Ripọtì
Which of the following may be used to explain a mirage?
I. Layers of air near the road surface have varying refractive indices in hot weather
II. Road surfaces sometimes become good reflectors in hot weather
III. Light from the sky can be reflected upwards after coming close to the road surface.
Akọwa Nkọwa
The phenomenon of a mirage can be explained by options I and III. A mirage is an optical illusion that occurs when light rays passing through a medium with varying refractive indices create a false image of distant objects or even the sky. In hot weather, the air near the road surface becomes hotter and less dense than the air above, causing the light passing through it to bend and create a reflection of the sky or objects in the distance. This effect is known as a temperature inversion. Additionally, light from the sky can be reflected upwards after coming close to the road surface, adding to the illusion of a reflected object or the sky. Option II, which suggests that road surfaces become good reflectors in hot weather, is not a valid explanation for a mirage. Therefore, the correct answer is: I and III only.
Ajụjụ 27 Ripọtì
Which of the following instruments is most suitable for measuring the outside diameter of a narrow pipe in a few millimeters in diameter?
Akọwa Nkọwa
The most suitable instrument for measuring the outside diameter of a narrow pipe in a few millimeters in diameter is a micrometer screw gauge.
A micrometer screw gauge is a precision measuring instrument that can accurately measure small dimensions with high accuracy. It has a spindle that moves towards an anvil and a scale that indicates the measurement. The spindle moves in response to a small rotation of the thimble, allowing for precise and sensitive measurements.
In contrast, a pair of calipers or a meter rule may not be accurate enough for measuring such small dimensions, and a tape rule may not be able to fit inside the narrow pipe. Therefore, a micrometer screw gauge is the most suitable option for measuring the outside diameter of a narrow pipe in a few millimeters in diameter.
Ajụjụ 28 Ripọtì
The pitch of an acoustic device can be increased by
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The pitch of an acoustic device refers to the perceived highness or lowness of a sound, and is determined by the frequency of the sound wave. To increase the pitch of an acoustic device, you need to increase the frequency of the sound wave. This can be done by increasing the number of vibrations per second that the device produces.
So, the correct answer is to "increase the frequency".
Ajụjụ 29 Ripọtì
A boy receives the echo of his clap reflected by a nearby hill 0.8s later. If the speed of sound in air is 3.40ms\(^{-1}\), how far is he from the hill?
Akọwa Nkọwa
The speed of sound in air is given as 3.40 m/s. The echo of the clap is heard 0.8 seconds after it was produced, which means it traveled to the hill and back. The time taken for sound to travel to the hill is half of the time taken for it to travel to and from the hill. Therefore, the time taken for sound to travel to the hill is 0.8/2 = 0.4 seconds.
We can use the formula:
distance = speed x time
to calculate the distance between the boy and the hill.
distance = speed of sound x time taken for sound to travel to the hill
distance = 3.40 m/s x 0.4 s
distance = 1.36 m
Therefore, the distance between the boy and the hill is 1.36 meters.
However, the answer options provided are in meters and are significantly larger than 1.36 meters. It is possible that the speed of sound provided in the question is incorrect or the answer options are incorrect.
Ajụjụ 30 Ripọtì
Which of the following concepts is not an evidence of the particles nature of matter?
Akọwa Nkọwa
The particle nature of matter refers to the idea that matter is made up of tiny particles that are constantly moving. Diffusion, Brownian motion, and crystallization are all examples of phenomena that can be explained by the particle nature of matter.
However, diffraction is not an evidence of the particle nature of matter. Diffraction is a phenomenon that occurs when waves encounter an obstacle or a slit, causing them to spread out and interfere with each other. While particles can also exhibit diffraction, this is a property of waves and is not specific to particles.
In summary, diffusion, Brownian motion, and crystallization are all evidences of the particle nature of matter, but diffraction is not.
Ajụjụ 31 Ripọtì
The electrochemical equivalent of silver is 0.0012g/C. If 36.0g of silver is to be deposited by electrolysis on a surface by passing a steady current for 5mins, the current must be?
Akọwa Nkọwa
The electrochemical equivalent of silver is a measure of the amount of silver that is deposited on a surface per unit of charge. In this case, the electrochemical equivalent of silver is 0.0012 grams per Coulomb of charge. To deposit 36.0 grams of silver by electrolysis, we need to know the amount of charge that must be passed through the solution.
The amount of charge is given by:
Q = m/z
where m is the mass of silver to be deposited, 0.0012 is the electrochemical equivalent of silver, and z is the charge on one mole of electrons (z = 1 for a single electron).
So, the amount of charge required is:
Q = 36.0 g / 0.0012 g/C = 30000 C
The current, I, is given by:
I = Q / t
where t is the time for which the current is flowing. In this case, t = 5 minutes.
So, the current required is:
I = 30000 C / (5 x 60 s) = 100 A
Therefore, the current must be 100 Amperes.
Ajụjụ 32 Ripọtì
Electrical power is transmitted at a high voltage rather than a low voltage because the amount of energy loss is due to
Akọwa Nkọwa
The primary reason that power is transmitted at high voltages is to increase efficiency. As electricity is transmitted over long distances, there are inherent energy losses along the way. High voltage transmission minimizes the amount of power lost as electricity flows from one location to the next. How? The higher the voltage, the lower the current. The lower the current, the lower the resistance losses in the conductors. And when resistance losses are low, energy losses are low also. Electrical engineers consider factors such as the power being transmitted and the distance required for transmission when determining the optimal transmission voltage
Ajụjụ 33 Ripọtì
Convex mirrors are used as driving mirrors because images formed are
Akọwa Nkọwa
Convex mirrors are used as driving mirrors because the images formed by them are "erect, virtual, and diminished."
Let me explain what these terms mean:
- Erect: It means that the image appears upright, just like the actual object. This is important for a driving mirror because it allows the driver to perceive the correct orientation of the vehicles behind them.
- Virtual: It means that the image appears to be behind the mirror, and not in front of it. This is also important for a driving mirror because it allows the driver to see a wider field of view without having to turn their head.
- Diminished: It means that the image is smaller than the actual object. This is important for a driving mirror because it allows the driver to see a larger area behind them while still fitting it within the mirror's frame.
Overall, these properties make convex mirrors ideal for use as driving mirrors as they provide the driver with an accurate view of the vehicles behind them without sacrificing their field of view.
Ajụjụ 34 Ripọtì
An object moves in a circular path of radius 0.5m with a speed of \(1ms^{-1}\). What is its angular velocity?
Akọwa Nkọwa
Angular velocity is a measure of how fast an object is rotating around a center point. It's usually measured in radians per second (rad/s).
To calculate angular velocity, we use the formula: angular velocity = linear velocity / radius. In this case, the linear velocity is 1 m/s, and the radius is 0.5 m.
So, the angular velocity would be:
1 m/s / 0.5 m = 2 rad/s
Therefore, the answer is 2 rad/s or 2rads^-1
Ajụjụ 35 Ripọtì
What is the resultant resistance of the circuit in the image shown?
Akọwa Nkọwa
Formulae resistance in parallel
= 1/R = 1/R1 +1/R2
1/R = 1/2 +1/2 = 1
Resistance are now in series
R = 1 + 3 + 4
= 8 ohms
= 1/R = 1/R1 +1/R2
1/R = 1/2 +1/2 = 1
Resistance are now in series
R = 1 + 3 + 4
= 8 ohms
Ajụjụ 36 Ripọtì
The resistance of a 40W car head lamp, drawing current from a 12V battery is ____.
Akọwa Nkọwa
The resistance of a 40W car headlamp can be calculated using Ohm's Law, which states that the current (I) flowing through a conductor between two points is directly proportional to the voltage (V) across the two points, and inversely proportional to the resistance (R) of the conductor. The equation can be written as V = IR.
Since the power (P) of the headlamp is given as 40W and the voltage is 12V, we can calculate the current using the equation P = IV. Substituting I = P/V, we get I = 40/12 = 3.33A.
Finally, using Ohm's Law, we can calculate the resistance as R = V/I = 12/3.33 = 3.6Ω.
So, the resistance of the 40W car headlamp, drawing current from a 12V battery, is 3.6Ω.
Ajụjụ 37 Ripọtì
Mercury which is spilled onto a glass surface forms ball-like shapes because____.
Akọwa Nkọwa
In case of small drops of mercury, the gravitational potential energy is negligible in comparison to the potential energy due to surface tension.Consequently, to keep the drop in equilibrium, the mercury drop’s surface tends to contract so that its surface area will be the least for a sphere and the drops will be spherical.
But in the case of bigger drops of mercury, the potential energy due to gravity is predominant over the potential energy due to surface tension.Consequently, to keep equilibrium , the mercury drop tends to assume minimum potential energy as possible, the drop becomes oval in shape and lower center of gravity.
But in the case of bigger drops of mercury, the potential energy due to gravity is predominant over the potential energy due to surface tension.Consequently, to keep equilibrium , the mercury drop tends to assume minimum potential energy as possible, the drop becomes oval in shape and lower center of gravity.
Ajụjụ 38 Ripọtì
Musical instruments playing the same note can be distinguished from one another owing to the difference in their
Akọwa Nkọwa
Different musical instruments playing the same note can be distinguished from one another due to the difference in their "timbre" or "tone color." Timbre refers to the unique character or quality of a sound that allows us to distinguish it from other sounds even when they have the same pitch and loudness. For example, a piano and a guitar playing the same note will sound different due to the differences in their timbre. This is why we can tell the difference between different instruments and why some instruments are better suited to certain styles of music than others.
Ajụjụ 39 Ripọtì
Which of the following is not a product of nuclear fusion?
Akọwa Nkọwa
Neutron is not a product of nuclear fusion. Nuclear fusion is the process by which two or more atomic nuclei come together to form a heavier nucleus, releasing a large amount of energy in the process. In most fusion reactions, the resulting products are alpha particles (helium nuclei) and energy in the form of gamma rays.
X-rays and gamma rays are both forms of high-energy electromagnetic radiation that can be produced by nuclear reactions, including nuclear fusion. Alpha particles are also a common product of nuclear fusion, especially in the fusion reactions that power the sun.
However, neutrons are not typically produced in fusion reactions. In fact, one of the major challenges in developing fusion as a practical energy source is finding ways to produce and control the high-energy neutrons that are generated in the process. Neutrons can be produced in some types of fusion reactions, but they are not a primary product.
In summary, neutron is not a product of nuclear fusion, while X-rays, Y-rays (assuming this is a valid form of radiation), and alpha particles are common products of this process.
Ajụjụ 40 Ripọtì
If the focal length of a camera is 20cm, the distance from the film at which the lens must be set to produce a sharp image of 100cm away is
Akọwa Nkọwa
F = 20cm
V = 100cm
U = ?
1U + 1V = 1F
120 + 1100 = 1F
5+1100 = 1F
F = 1006
= 16.7cm
= 17cm
V = 100cm
U = ?
1U + 1V = 1F
120 + 1100 = 1F
5+1100 = 1F
F = 1006
= 16.7cm
= 17cm
