JAMB UTME - Physics - 1991 | Green Bridge CBT

Question 1 Report

The saturated vapour pressure of a liquid increases as the

volume of the liquid increases

volume of the liquid decreases

temperature of the liquid increases

temperature of the liquid decreases

Vapours

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Question 2 Report

Find the tension T1 in the diagram above if the system is in equilibrium. [G = 10ms-2]

200/√3N

100/√3N

300/√3N

100N

Equilibrium Of Forces

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Question 3 Report

The absolute temperature of a perfect gas is proportional to the average

potential energy of the molecules

seperation between the molecules

kinetic energy of the molecules

velocity of the molecules

Temperature And Its Measurement

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Question 4 Report

A body of mass 100g moving with a velocity of 10.0ms-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

Newton’s Laws Of Motion

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Question 5 Report

Which of the following phenomena is called photoelectric effect?

high energy electrons impinge on a metalic anode which then emits photons

a high energy photon emits photons as it slowed down

a metal absorbs quanta of light and then emits electrons

Two electrons are created from a quantum of light

Electromagnetic Field (Part 2)

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Question 6 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)

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Question 7 Report

Two tuning forks of frequency 256Hz and 260Hz are sounded close to each other. What is the frequency of the beats produced?

2Hz

4Hz

8Hz

258Hz

Propagation Of Sound Waves

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Question 8 Report

A trough 12.0cm deep is filled with water of refractive index $ \frac{4}{3} $. By how much would a coin at the bottom of the trough appear to be displaced when viewed vertically from above the water surface?

3.0cm

6.0cm

9.0cm

16.0cm

Answer Details

\frac{4}{3}

=

\frac{12}{Apparent depth}

Apparent depth = 9cm

Height by which coin is raised = 12 - 9

= 3cm

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

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

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Question 9 Report

The spiral spring of a spring balance is 25.0cm long when 5N hangs on it and 30cm long, when the weight is 10N. What is the length of the spring if the weight is 3N assuming Hooke's law is obeyed?

15.0cm

17.0cm

20.0cm

23.0cm

Answer Details

let the length be Lcm

$\frac{5 - 3}{25 - L}$ = $\frac{10 - 5}{30 - 25}$

L = 23cm

Read lesson note on Elasticity (JAMB)

Elasticity

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Question 10 Report

To convert an alternating current dynamo into a direct current dynamo, the

number of turns in the coil is increased

strength of the field magnet is increased

slip rings are replaced with a split ring commutator

coil is wound on a soft iron armature

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Question 11 Report

Which of the following are True for $ \alpha $-decay. i. mass number, decrease by four. ii. Atomic number decreases by two. iii. mass number does not change.

i and ii only

ii and iii only

i and iii only

i, ii, and iii only

Simple A.C. Circuits

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Question 12 Report

How long does it take a 750W heater to raise the temperature of 1kg of water from 20oC to 50oC [specific heat capacity of water = 4200Jkg-1K-1]

84s

112s

168s

280s

Heat Energy

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Question 13 Report

The net capacitance of the circuit shown above is

8.0µF

6.0µF

4.0µF

2.0µF

Capacitors

Current Electricity

Simple A.C Circuits

Measurements And Units

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Question 14 Report

A brass rod is 2m long at a certain temperature. What is the length for a temperature rise of 100K, if the expansivity of brass is 18 x 10-6K-1?

2.0036m

2.0018cm

2.1800

2.0360m

Thermal Expansion

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Question 15 Report

Which of the following statements is CORRECT about the earth's magnetic field?

the angle of dip is the angle which a freely suspended magnet makes with the vertical

the angle of declination is the angle between the magnetic meridian and the geographic meridian

the angle of declination is the angle which a magnetic compass makes with the magnetic meridian

the angle of inclination is the difference between the angle of dip and the angle of declination

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Question 16 Report

Which of the following is TRUE of light and sound waves?

they both transmit energy

they both need a mediumfor propagation

they are both transverse waves

their velocities in air are equal

Sound Waves

Light Energy

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Question 17 Report

A pilot records the atmospheric pressure outside its plane as 63cm of Hg while a ground observer records a reading of 75cm of Hg for the atmospheric pressure on the ground. Assuming that the density of the atmosphere is constant, calculate the height of the plane above the ground. (Relative density of Hg = 13.0 and that of air = 0.00013)

1200m

6300m

7500m

13800m

Answer Details

Difference in pressure = 75 - 63

= 12cmHg

pressure = hge

difference in height = $\frac{12}{10 \times \frac{0.00013}{13}}$

= 1200m

Read lesson note on Pressure (JAMB)

Pressure

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Question 18 Report

In the above circuit, The fuse wire melts when

K is Opened

K is closed

the 14 ohm resistor is doubled with k closed

the 6 ohm resistor is doubled with k closed

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Question 19 Report

Which of the following obeys Ohm's Law?

Glass

Diode

All electrolytes

All metals

Electrostatics

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Question 20 Report

A moving coil galvanometer of $300\,\Omega$ resistance gives full scale deflection for 1.0mA. The resistance R, of the shunt that is required to convert the galvanometer into a 3.0A ammeter is

899.70

Ω

10.00

Ω

Ω

Ω

0.01

Ω

Electrostatics

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Question 21 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

Answer Details

v =

λ

F

260 x 1.29 =335.4ms-1

Echo time = $\frac{2}{2}$ = 1sec.

distance = v x t

= 335.4 x 1 = 335.4m

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

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

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Question 22 Report

A 20kg mass is to be pulled up a slope inclined at 30o to the horizontal. If the efficiency of the plane is 75%, the force required to pull the load up the plane is [g = 10ms-2]

13.3N

73.5N

133.3N

53.2N

Equilibrium Of Forces

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Question 23 Report

4g of a radioactive material of half-life 10 days is spilled on a laboratory floor. How long would it take to disintegrate 3.5g of the material?

1

\frac{1}{4}

days

8

\frac{1}{4}

days

30 days

80 days

Heat Energy

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Question 24 Report

The image in a pin-hole camera is

errect and formed by refraction through a lens

virtual and formed by dispersion

erect and gets sharper as the hole becomes larger

inverted and formed by the light from each point travelling in a straight line

Electrostatics

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Question 25 Report

In a ray diagram for a thin converging lens, a ray that is not parallel to the optic axis but passes through the optic center will

pass through undeviated

pass through the center of curvature after refraction

emerge parallel to the principal axis

pass through the principal focus after refraction

Reflection Of Light At Plane And Curved Surfaces

Optical Instruments

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Question 26 Report

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

convection

radiation

conduction

reflection

Answer Details

The occupant of the room standing away from the charcoal fire is mainly warmed by radiation. Radiation is the transfer of heat energy in the form of electromagnetic waves that can travel through empty space. In this case, the heat energy from the charcoal fire is transferred to the surrounding objects and the walls of the room through radiation. The objects and walls then re-radiate the heat energy towards the occupant, warming them up. Convection is the transfer of heat energy through the movement of fluids or gases, but in this scenario, the air in the room is not moving enough to contribute significantly to the warming of the occupant. Conduction is the transfer of heat energy through direct contact between objects, but the occupant is not in direct contact with the fire or the walls of the room. Reflection is the bouncing back of electromagnetic waves from a surface, but it does not play a significant role in the warming of the occupant in this scenario.

Read lesson note on Heat Transfer (JAMB)

Read lesson note on Structure Of The Nucleus (WAEC)

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

Read lesson note on Liquids At Rest (JAMB)

Heat Transfer

Structure Of The Nucleus

Electromagnetic Field (Part 1)

Liquids At Rest

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Question 27 Report

A small metal ball thrown vertically upwards from the top of a tower with an initial velocity of 20ms-1. If the ball took a total of 6s to reach ground level, determine the height of the tower [g = 10ms-2]

60m

80m

100m

120m

Answer Details

Time from tower to top, t =

\frac{u - v}{g}

= $\frac{20 - 0}{10}$

= 2s

distance from tower to top

x = ut - $\frac{1}{2}$ gt2

= (20 x 2) - ( $\frac{1}{2}$ x 10 x 2 x 2)

= 20m

Time from the top to the ground, t = 6 - 2

= 4s

distance from top to ground,

x = ut - $\frac{1}{2}$ gt2

= (0 x 4) + ( $\frac{1}{2}$ x 10 x 4 x 4)

= 80cm

therefore, height of tower = 80 - 20

= 60m

Read lesson note on Motion (JAMB)

Motion

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Question 28 Report

A wheel and axle have radii 80cm and 10cm respectively. If the efficiency of the machine is 0.85, an applied force of 1200N to the wheel will raise a load of

8.0N

6.8N

8160N

9600N

Answer Details

Efficiency = m.A x

\frac{1}{V . R}

x 100%

85 = $\frac{l o a d}{1200}$ x $\frac{10}{80}$ x $\frac{100}{1}$

load = 8160N

Read lesson note on Simple Machines (JAMB)

Simple Machines

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Question 29 Report

A body is under action of a force F such that the force displacement graph of the body is semi circular as shown above. The work done on the body by the force in moving through 24 meters is

36π J

72π J

144π J

288π J

Work, Energy And Power

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Question 30 Report

When the bottom tip of a vibrating tuning fork is held in contact with a wooden box, a louder sound is heard. This phenomenon is known as

beats

echoing

resonance

reverberation

Sound Waves

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Question 31 Report

In a nuclear fusion process, four protons each of mass Mp were fused to produce a nucleus X of mass Mx. Which of the following equations is CORRECT?

4Mp > Mx

4Mp = Mx

4Mp< Mx

Mp > Mx

Structure Of The Nucleus

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Question 32 Report

A thermometer with an arbitrary scale S, of equal division registers -30oS at the ice point and +90oS at the steam point. Calculate the Celsius temperature corresponding to 60oS

25.0oC

50.0oC

66.7oC

75.0oC

Temperature And Its Measurement

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Question 33 Report

A spring of force constant 1500Nm-1 is acted upon by a constant force of 75N. Calculate the potential energy stored in the string

1.9J

2.8J

3.45J

0.43J

Answer Details

P.E =

\frac{1}{2}

Fe

= $\frac{1}{2}$ $\frac{F}{K}$

= $\frac{1}{2}$ x $\frac{75 \times 75}{1500}$

= 1.9J

Read lesson note on Elasticity (JAMB)

Elasticity

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Question 34 Report

What is the difference in the amount of heat given out by 4kg of steam and 4kg of water when both are cooled from 100oC to 80oC? [the specific latent heat of steam is 2,260,000Jkg-1, specific heat capacity of water is 4200Jkg-1K-1]

4200J

2,260,OOOJ

9,040,000J

9,380,000J

Answer Details

Heat by water = mc

θ

Heat by steam = mc $θ$ + mL

Difference = mL = 4 x 2,260,000

= 9,040,000J

Read lesson note on Heat Energy (WAEC)

Heat Energy

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Question 35 Report

An equipment whose power is 1500W and resistance is 375 ohms would draw a current of

0.10A

2.00A

4.00A

77.5A

Current Electricity

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Question 36 Report

An insulated rod when rubbed with a material acquires

a negative charge if it is made of glass and rubbed with silk

no charge if it is made of glass and rubbed with fur

no charge if it is made of copper and rubbed with silk

a positive charge if it is made of copper and rubbed with fur

Electrostatics

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Question 37 Report

The mass of a stone is 15.0g when completely immersed in water and 10.0g when completely immersed in a liquid of relative density 2.0. The mass of the stone in air is

5.0g

12.0g

20.0g

25.0g

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Question 38 Report

The function of the system of granulated carbon mixed with manganese (IV) oxide in a Letanche cell is to

increase the e.m.f. of the cell to 2.0V

prevent local action in the cell

prevent polarisation in the cell

make the cell black and hence a good radiator

Electrostatics

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Question 39 Report

A body of weight W N rest on a smooth plane inclined at an angle $ \theta $^o to the horizontal. What is the resolved part of the weight in Newtons along the plane?

θ

W cos

θ

W sec

θ

W tan

θ

Equilibrium Of Forces

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Question 40 Report

An object moves with uniform speed round a circle. Its acceleration has

constant magnitude and constant direction

constant magnitude and varying direction

varying magnitude but constant direction

varying magnitude and varying direction

Rectilinear Acceleration

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Question 41 Report

The electrochemical equivalent of platinum is 5.0 x 10-7kgC-1 to plate-out 1.0kg of platinum, a current of 100A must be passed through an appropriate vessel for

5.6 hours

56 hours

1.4 x 104 hours

2.0 x 104 hours

Electric Cells

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Question 42 Report

Which of the following correctly, describes the image of an object, 4cm from a diverging lens of focal length 12cm?

The image is virtual, 3cm in front of the lens

The image is real, 6cm behind the lens

The image is virtual, 6cm in front of the lens

The image is real, 3cm in front the lens

Answer Details

F =

\frac{u v}{u + v}

F = -ve

-12 = $\frac{4 \times v}{4 + v}$

v = -3cm

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

Structure Of The Atom (Nigeria Only)

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Question 43 Report

When a plane mirror at which a ray is incident is rotated through an angle $\theta$, the reflected ray will be rotated through

\frac{1}{2}

θ

θ

2

θ

3

θ

Refraction Of Light Through Plane And Curved Surfaces

Electrostatics

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Question 44 Report

If a current carrying coil is mounted on a metal frame, the back e.m.f. induced in the coil causes

inductance

eddy currents

elecro-magnetism

dipole moment

Electromagnetic Field (Part 2)

Electrostatics

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Question 45 Report

Which of the following is the most suitable for use as an altimeter?

A mecury barometer

A fortin barometer

A mecury manometer

An aneroid barometer

Pressure

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Question 46 Report

In which of the following is surface tension important?

the floating of a ship in water

the floating of a dry needle in water

the floating of a baloon in air

the diffusion of sugar solution across a membrane

Temperature And Its Measurement

Pressure

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Question 47 Report

When an atom loses or gains a charge, it becomes

an electron

an ion

a neutron

a proton

Structure Of The Atom (Nigeria Only)

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Question 48 Report

The internal resistance of each of the cells E1 and E2 Shown in the figure above is 2 Ohm. Calculate the total current in the circuit

0.80A

0.50A

0.40A

0.004A

Current Electricity

Work, Energy And Power

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Question 49 Report

A boy timed 30 oscillations of a certain pendulum thrice and obtained 1min. 10s, 1min. 12s and 1min. 7s respectively.The mean period of oscillation of the pendulum is

0.14s

0.43s

2.32s

6.97s

Simple Harmonic Motion

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