Which of the following does NOT describe the Image formed by a plane minor?

Same distance from mirror as object

A positively charged rod X is brought near an uncharged metal sphere Y and is then touched by a finger with X still in place. When the finger is removed, the result is that Y has

a negative charge and a negative potential

a positive charge and a zero potential

a negative charge and a positive potential

a negative charge and a negative potential

Convex mirrors are used as driving mirrors because images formed are

inverted, virtual and diminished

Which of the following is true of an electrical charge?

Positive charge means deficit electrons

Negative charge means excess of electrons

electric current means movement of electrons

The time rate of loss of heat by a body is proportional to the

difference in temperature between the body and its surroundings

temperature of its surroundings

difference in temperature between the body and its surroundings

ratio of the temperature of the body to that of its surroundings

In homes, electrical appliances and lamps are connected in parallel because

series connection uses high voltage

parallel connection does not heat up the wires

series connection uses high voltage

The photo cell works on the principle of the

Emission of electron by incident radiation

Emission of protons by incident radiation

Electrical appliances in homes are normally earthed so that

a person touching the appliances is safe from electric shock

both the a.c. and d.c. sources can be used

the appliances are maintained at a higher pd than the earth

the appliances are maintained at a lower pd than the earth

Natural radioactivity consists of the emission of

α- particles, β - rays and g-rays

JAMB UTME - Physics - 2018 | Green Bridge CBT

Question 1 Report

The efficiency of energy conversion on the energy flow through a hydroelectric power is?

E1

E2

\frac{E 3}{E 2}

\frac{E 2}{E 1}

+ E2

\frac{E 2}{E 3}

+ E1

Answer Details

Efficiency =

\frac{useful energy output from machine}{energy input into machine}

=

\frac{E 3}{E 2}

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

Work, Energy And Power

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Question 2 Report

A car traveled at a uniform speed of 100km/h, spends 15m moving from point A to point B along its route. The distance between A and B is

50km

25km

15km

10km

View Answer

Question 3 Report

A body of mass 100g moving with a velocity if 10ms-1 collides with a wall. If after collision it moves with a velocity of 2.0ms−1 in the opposite direction, calculate the change in momentum.

0.8Ns

1.2Ns

12.0Ns

80.0Ns

Answer Details

Momentum = Mass x Velocity
Change in Momentum = Mass x (change in velocity)
Change in Momentum = Mass x (v - u)
Mass = 100g = 0.1kg
U = 2ms

^{- 1}

V = 10ms

^{- 1}

Change in momentum = m (v − u)
= 0.1 (10 − 2)
= 0.1 (8)
= 0.8Ns

Read lesson note on Motion (JAMB)

Motion

View Answer

Question 4 Report

Temperature is the property of a body which is proportional to the ____.

total kinetic energy of its molecules

average kinetic energy of its molecules

average speed of its molecules

maximum speed of its molecules

Temperature And Its Measurement

View Answer

Question 5 Report

Cathode rays are

High-energy electromagnetic waves

protons

neutrons

streams of electrons

Electric Field

Electromagnetic Field (Part 2)

View Answer

Question 6 Report

For what values of F and ? will the forces shown in the diagram below be in equilibrium.

60N and 60

^{o}

60N and 30

^{o}

20?3 N and 60

^{o}

20?3N and 30

^{o}

Answer Details

Resolve vertically, 40cos? = 20, ? = 60

^{o}

Resolve horizontally, f = 40sin? = 40sin60

^{o}

= 40(

\frac{\sqrt{3}}{2}

)
= 20?3 N

Read lesson note on Equilibrium Of Forces (WAEC)

Equilibrium Of Forces

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Question 7 Report

Which of the following best describes the energy changes which take place when a steam engine drives a generator which lights a lamp?

heat ----> Light----> Sound ----> Kinetic

Kinetic ----> Light ----> Heat ----> Electricity

heat ----> Kinetic ----> Electricity ----> Heat and Light

electricity ----> Kinetic ----> Heat ----> Light

Production And Propagation Of Waves

Energy

Heat Energy

Work, Energy And Power

View Answer

Question 8 Report

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

15

^{o}

18

^{o}

22

^{o}

24

^{o}

Answer Details

X =

\frac{4}{3}

r = ?
Shell?s law:. 7 =

\frac{S i n 2^{0}}{S i n r^{0}}

\frac{V}{g}

=

\frac{S i n 30^{0}}{S i n r^{0}}

Sin

r^{0}

=

\frac{3 S i n 30^{0}}{4}

Sin

r^{0}

= 0.375
R

^{o}

= Sin-1 (0.375)
R

^{o}

= 22.02

^{o}

R

^{o}

= 22

^{o}

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

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

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

Refraction Of Light Through Plane And Curved Surfaces

View Answer

Question 9 Report

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?

0Nm

3Nm

7Nm

10Nm

Scalars And Vectors

Equilibrium Of Forces

View Answer

Question 10 Report

Which of the following is an essential physical property of the wires uses for making fuses ?

Low density

Hypothermal conductivity

Low electrical resistivity

Low melting point

Gravitational Field

Electrostatics

View Answer

Question 11 Report

When an atom loses or gain a charge it becomes

An electron

An ion

A neutron

A proton

Electrostatics

View Answer

Question 12 Report

The tendency of a body to remain at rest when a force is applied to it is called.

Impulse

Momentum

Inertia

Friction

Scalars And Vectors

Equilibrium Of Forces

View Answer

Question 13 Report

An object is placed 20cm from a concave mirror of focal length 10cm. The linear magnification of the image produced is?

0

1

2

1

2

Electrostatics

View Answer

Question 14 Report

The differences observed in solids, liquids and gases may be accounted for by

their relative masses

their melting points

the spacing and forces acting between the molecules

the different molecules in each of them

Thermal Expansion

Structure Of Matter And Kinetic Theory

View Answer

Question 15 Report

The product of force and time is?

Impulse

Momentum

Inertia

Friction

Work, Energy And Power

View Answer

Question 16 Report

Mercury which is spilled onto a glass surface forms ball-like shapes because____.

Mercury is a metal

The cohesive force between its molecules is greater than the adhesive force between mercury and glass molecules

The cohesive force between its molecules is less than the adhesive force between mercury and glass molecules

The viscosity of mercury is height

Liquids At Rest

View Answer

Question 17 Report

A lens of focal length 15cm forms on erect image which is three times the size of the object. The distance between the object and the image is ___.

10cm

20cm

30cm

40cm

Optical Instruments

View Answer

Question 18 Report

In a series R-L-C circuit at resonance, the voltages across the resistor and the inductor are 30V and 40V respectively. What is the voltage across the capacitor?

30V

70V

50V

40V

View Answer

Question 19 Report

Which of the following obeys Ohm's law?

all metals

diode only

all electrolytes

glass

Electrostatics

View Answer

Question 20 Report

An object moves in a circular path of radius 0.5m with a speed of $1ms^{-1}$. What is its angular velocity?

8rads

^{- 1}

4rads

^{- 1}

1rads

^{- 1}

2rads

^{- 1}

Motion

Speed And Velocity

View Answer

Question 21 Report

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

20.0kgms

^{- 1}

10.0kgms

^{- 1}

5.0kgms

^{- 1}

2.5kgms

^{- 1}

Newton’s Laws Of Motion

Work, Energy And Power

Equilibrium Of Forces

View Answer

Question 22 Report

In the diagram given if the atmospheric pressure is 760mm, the pressure in the chamber G Is

660mm

890mm

690mm

860mm

Pressure

View Answer

Question 23 Report

A room is heated by means of a charcoal fire, an occupants of the room standing away from the fire is warmed mainly by

Convection

Radiation

Conduction

Reflection

Heat Transfer

Gravitational Field

Conduction Of Electricity Through

View Answer

Question 24 Report

A resistor connected to a 12V battery draws a current of 2A. The energy dispatched in the resistor in 5 minutes is ___.

3,600J

6,000J

7,200J

14,400J

Electrical Energy And Power

View Answer

Question 25 Report

Musical instruments playing the same note can be distinguished from one another owing to the difference in their

quality

pitch

intensity

loudness

View Answer

Question 26 Report

A narrow beam of white light can be split up into different colours by a glass prism. The correct explanation is that

white light Is an electromagnetic wave

the prism has all the colours of the white light

different colours of white light travel with different speeds in glass

white light has undergone total Internal reflection in the prism

Answer Details

The correct explanation for why a narrow beam of white light can be split up into different colors by a glass prism is that different colors of white light travel with different speeds in glass. White light is made up of different colors with different wavelengths, ranging from violet to red. When a narrow beam of white light passes through a glass prism, the different colors refract at slightly different angles due to the fact that their wavelengths are different. This causes the different colors to spread out and form a spectrum. The amount of refraction that occurs depends on the speed of light in the medium. Different colors of light have different speeds in glass due to the fact that their wavelengths are different. This means that they will refract at different angles as they pass through the glass prism, causing them to spread out. So, the correct explanation for why a narrow beam of white light can be split up into different colors by a glass prism is that different colors of white light travel with different speeds in glass. Therefore, is the correct explanation. is incorrect because it describes what white light is made up of, but does not explain how it is split up into colors by a prism. is incorrect because a prism does not have all the colors of white light, but rather it separates the colors that are already present in white light. is incorrect because total internal reflection occurs when light is completely reflected back into the same medium, which is not what happens when white light is split up by a prism.

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

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

View Answer

Question 27 Report

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?

66m

136m

264m

528m

View Answer

Question 28 Report

What flows to the earth by connecting the conductor to the earth?

Electrons

Ion

Neutron

Proton

Electrostatics

View Answer

Question 29 Report

A solid cube of side 50cm and mass 75kg floats in a liquid with $ \frac{1}{3} $ of its height above the liquid surface. The relative density of the liquid is?

0.33

0.50

0.67

0.90

Answer Details

Volume of liquid displaced
=

\frac{2}{3}

(0.5)

^{3}

Mass of liquid displaced = mass of floating cube = 75kg
Density of liquid =

\frac{m a s s}{v o l u m e}

=

\frac{75}{(\frac{7}{3 (0.5)})}

× 3
= 0.9 × 103kgm

^{- 3}

R.D of liquid =

\frac{(0.9)}{(1.0)}

× 103
= 0.9

View Answer

Question 30 Report

An object weighs 30N in air and 21N in water. The weight of the object when completely immersed in a liquid of relative density 1.4 is

25.2N

17.4N

12.6N

9.0N

Answer Details

Weight of water displaced = upthrust = 30 - 21 = 9N
Mass of water displaced = $\frac{9}{10}$ = 0.9kg
Volume of object = 9 × 10 $^{- 4}$ m $^{3}$
= (9 × 10 $^{- 4}$ ) (1.4 ×103)

= 1.26kg = 12N
30 - 12.6 = 17.4N

Read lesson note on Gravitational Field (JAMB)

Gravitational Field

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Question 31 Report

Which of the following phenomena cannot be explained by the molecular theory of matter?

Conduction

Convection

Expansion

Radiation

Thermal Expansion

View Answer

Question 32 Report

Which of the following has the lowest internal resistance when new?

Leclanche cell

Daniell cell

Torch battery

Accumulator

Answer Details

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.

Read lesson note on Current Electricity (JAMB)

Read lesson note on Electric Cells (JAMB)

Read lesson note on Gravitational Field (JAMB)

Current Electricity

Electric Cells

Gravitational Field

View Answer

Question 33 Report

Calculate the effective capacitance of the circuit in the diagram given

4μf

3μf

2μf

1μf

View Answer

Question 34 Report

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

I and II only

I and III only

II and III only

I, II and III

Structure Of The Atom (Nigeria Only)

View Answer

Question 35 Report

Which of the following is not a product of nuclear fusion?

X – ray

Y –ray

α – particles

neutron

Magnetic Field (Part 2)

Electromagnetic Field (Part 2)

View Answer

Question 36 Report

Electrical power is transmitted at a high voltage rather than a low voltage because the amount of energy loss is due to

Heat dissipation

Production of eddy currents

Excessive current discharge

Excessive voltage discharge

View Answer

Question 37 Report

Palm oil from a bottle flows out more easily after it has been heated because the

Molecules are given energy during the heating

Friction between oil layers is reduced

Oil molecules force each other out

Adhesion between the oil molecules and those of the bottle is increased

Thermal Expansion

Structure Of Matter And Kinetic Theory

View Answer

Question 38 Report

Which of the following diagrams represents correctly an n-p-n transistor?

i.

ii

iii

i

ii

iii

View Answer

Question 39 Report

A man hears his echo from a nearby hill 2s after he shouted. If the frequency of his voice is 260Hz and the wavelength is 1.29m, how far away is the hill

330.0m

335.4m

660.0m

670.8m

Production And Propagation Of Waves

Sound Waves

View Answer

Question 40 Report

The force between the molecules of a liquid in contact with that of a solid is?

Adhesive

Cohesive

Magnetic

Repulsive

Thermal Expansion

View Answer






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