JAMB UTME - Physics - 1997 | Green Bridge CBT

Question 1 Report

What happens when a, certain quantity of pure ice is completely changed to water at 0oC?

latent heat is absorbed, the mass remains constant, and the volume decreases

latent heat is given out, the mass remains constant and the volume decreases

latent heat is given out, the mass increases and the volume remains constant

latent heat is absorbed, the mass decreases and the volume increases

Quantity Of Heat

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Question 2 Report

At what respective values of X, Y and Z would the unit of force, the newton, be dimensionally equivalent to MxLyTz?

-1, 1, 2

1, 1, -2

1, -1, 2

-1, 1, -2

Fundamental And Derived Quantities And Units

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Question 3 Report

An electric water pump rate 1.5 kW, lifts 200kg of water through a vertical height of 6 meters in seconds. What is the efficiency of the pump? [g = 10ms-2, neglecting air resistance]

90.0%

85.0%

80.0%

65.0%

Answer Details

Efficiency = output x 100

= $\frac{\frac{200 \times 10 \times θ}{10}}{1500}$ x $\frac{100}{1}$

= 80%

Read lesson note on Electrical Energy And Power (JAMB)

Electrical Energy And Power

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Question 4 Report

A galvanometer of internal resistance $50\Omega$ has a full scale deflection for a current of $5\text{mA}$. What is the resistance required to covert it to a voltmeter with full scale deflection of $10\text{V}$?

1750

Ω

1950Ω

2000

Ω

2500

Ω

Current Electricity

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Question 5 Report

The distance xm travelled by a particle in time t seconds is described by the equation x = 10 + 12t2, Find the average speed of the particle between the time interval t = 2s and t = 5s

60 ms-1

72 ms-1

84 ms-1

108 ms-1

Answer Details

speed =

\frac{d x}{d t}

$\frac{d x}{d t}$ = 10 + 12t2

$\frac{d x}{d t}$ = 24t

$\frac{d x}{d t}$ =24 x 3

$\frac{d x}{d t}$ = 72 ms-1

Read lesson note on Motion (WAEC)

Motion

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Question 6 Report

The voltage of the domestic electric supply is represented by the equation $V = 311 \sin 314.2t$. Determine the frequency of the a.c. supply $[\pi = 3.142]$

50.0Hz

100.0Hz

311.0Hz

314.2Hz

Answer Details

V = 311 sin314.2t compare with,

V = V sin2 $π$ Ft

2 $μ$ F = 314.2

F = $\frac{314.2}{2 \times 3.142}$

F = 50Hz

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Question 7 Report

Three electric cells each of e.m.f 1.5V and internal resistance of 1.0 $\Omega$ are connected in parallel across an external resistance of $\frac{2}{3}\Omega$. Calculate the value of the current in the resistor

0.5 A

0.9A

1.5A

4.5A

Answer Details

E.m.f = 1.5

r = $\frac{1 \times 1 \times 1}{(1 \times 1) + (1 \times 1) + (1 \times 1)}$

r = $\frac{1}{3}$ $Ω$

I = $\frac{E . m . f}{r + R}$

I = $\frac{1.5}{\frac{1}{3} + \frac{2}{3}}$

I = 1.5A

Read lesson note on Current Electricity (JAMB)

Current Electricity

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Question 8 Report

A piece of wire gauze can be made to lie on water because

the wire guaze is less dense than water

the water molecules repels the wire guaze upwards

the water surface has the effect of an elastic thin skin

of the cohensive forces between the water and the wire guaze molecules

Fluid At Rest

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Question 9 Report

In a purely inductive circuit, the current

lags behind the voltage in phase by 90o

leads the voltage in phase by 90o

is in the same phase with the voltage

leads the voltage by 180o

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Question 10 Report

A body of mass 2kg moving vertically upwards has its velocity increased uniformly from 10ms-1 to 40ms-1 in 4s. Neglecting air resistance, calculate the upward vertical force acting on the body.[g = 10 ms-1]

15N

20N

35N

45N

Answer Details

F = mg + ma

F = 2 [10 + $\frac{(40 - 10)}{4}$ ]

F = 35 N

Read lesson note on Scalars And Vectors (WAEC)

Scalars And Vectors

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Question 11 Report

Ripples on water and light waves are similar because both

have the same frequency

can be refracted and diffracted

are longitudinal waves

have the same velocity

Current Electricity

Sound Waves

Properties Of Waves: Reflection, Refraction, Diffraction

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Question 12 Report

Two 50 $\mu$ Farad parallel plate capacitors are connected in series. The combined capacitor is then connected across a 100-V battery. The charge on each plate of the

5.00 x 10-5C

2.50 x 10-3C

1.25 x 10-3C

1.00 x 10-2C

Capacitors

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Question 13 Report

A 5kg block is released from rest on a smooth plane inclined at an angle of 30o to the horizontal. What is the acceleration down the plane? [g = 10ms-2]

5.0 ms-2

5.8 ms-2

8.7 ms-2

25.0 ms-2

Scalars And Vectors

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Question 14 Report

A mass of a liquid at 30oC is mixed with a mass of the same liquid at 70oC and the temperature of the mixture is 45oC. Find the ratio of the mass of the cold liquid to the mass of the other liquid.

3 : 5

5 : 3

3 : 7

7 : 3

Temperature And Its Measurement

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Question 15 Report

A load of 20N on a wire of cross-sectional area 8 x 10-7m2, produces an extension of 10m2. calculate Young's modulus for the material of the wire if its length is 3m

7.0 x 1011Nm-2

7.5 x 1011Nm-2

8.5 x 1011Nm-2

9.0 x 1011Nm-2

Elasticity

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Question 16 Report

The colours seen in the thin films of oil on the road and in soap bubbles are due to

reflection

interference

diffraction

polarization

Structure Of The Atom (Nigeria Only)

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Question 17 Report

When the sun, moon and the earth are as shown in the diagram above an observer standing in X is in

Penumbra and sees a partial eclipse

Penumbra and sees a total eclipse

umbra and sees a partial eclipse

umbra and sees a total eclipse

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Question 18 Report

What happens when a gas expands at constant temperature?

its pressure decreases

the total momentum of its molecules remains constant

its pressure decreases and the total momentum of its moleculees remains constant

its pressure decreses and the total kinetic energy of its molecule decreases

Gas Laws

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Question 19 Report

An empty 60 litre petrol tank has a mass of 10kg. Its mass when full of fuel of relative density 0.72 is

7.2kg

33.2kg

43.2kg

53.2kg

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Question 20 Report

The length of mercury thread when it is at 0^oC, 100^oC and at an unknown temperature $ \theta $ is 25mm, 225mm and 175mm respectively. The value of $ \theta $ is

85.0oC

80.0oC

75.0oC

70.0oC

Answer Details

\frac{θ - 0}{100 - 0}

=

\frac{175 - 25}{225 - 25}

$θ$ = 75.0oC

Read lesson note on Measurements And Units (JAMB)

Measurements And Units

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Question 21 Report

In the diagram above, which of the angles $ \theta_1 $, $ \theta_2 $, $ \theta_3 $ and $ \theta_4 $ is the angle of deviation of the ray of light passing through the glass prism XYZ?

θ3

θ2

θ_{1}

θ4

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Question 22 Report

An object of mass 100g projected vertically upwards from the ground level has a velocity of 20ms-1 at a height of 10m. calculate its initial kinetic energy at the ground level.[g = 10ms-2, neglect air resistance]

10 J

20 J

30 J

50 J

Answer Details

Using, v2 = u2 - 2gx

(20)2 = u21/2 x 10 x 10

u2 = 600(m/s)2

initial K.E = - mu2

= $\frac{1}{2}$ x 600

= 30 J

Read lesson note on Scalars And Vectors (WAEC)

Scalars And Vectors

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Question 23 Report

A cube of sides 0.1m hangs freely from a string. What is the upthrust on the cube when totally immersed in water? [density of water is 1000kgm-2, g = 10ms-2]

1000 N

700 N

110 N

10 N

Measurements And Units

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Question 24 Report

Under constant tension and constant mass per unit length, the note produced by a plucked string is 500Hz when the length of the string is 0.90m. At what length is the frequency 150Hz?

3m

4m

5m

6m

Answer Details

F =

\frac{1}{2 L}

\sqrt{\frac{T}{m}}

F1L1 = F2L2

500 x 0.9 = 150 x L2

therefore, L2 = 3m

Read lesson note on Motion (JAMB)

Motion

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Question 25 Report

Which of the following with respect to a body performing simple harmonic motion are in phase?

displacement and velocity of the body

displacement and force on the body

velocity and acceleration of the body

force acting on the body and the acceleration

Scalars And Vectors

Simple Harmonic Motion

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Question 26 Report

The graphite rods surrounding the uranium fuel rods in a nuclear reactor, are used to

absorb the neutrons and hence halt the nuclear process

create the neutrons and hence slow up the nuclear process

slowdown the neutrons and hence slow up the nuclear process

speed up the neutrons and hence speed up the nuclear process

Electromagnetic Field (Part 2)

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Question 27 Report

A planet has mass m1 and is at a distance r, from the sun. A second planet has mass m2 = 10m1 and at a distance of r2 = 2r1 from the sun. Determine the ratio of the gravitational force experienced by the planets.

1 : 5

2 : 5

3 : 5

4 : 5

Answer Details

g =

\frac{G M}{R^{2}}

$\frac{G_{1} M_{1}}{r_{1}^{2}}$ = $\frac{G_{2} M_{2}}{r_{2}^{2}}$

$\frac{G_{1} M_{1}}{r_{1}^{2}}$ = $\frac{G_{2} \times 10 M_{1}}{(2 r_{1})^{2}}$

$\frac{G_{1}}{G_{2}}$ = $\frac{2}{5}$

Read lesson note on Gravitational Field (JAMB)

Gravitational Field

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Question 28 Report

A liquid of mass 1.0 x 103kg fills a rectangular tank of length 2.5m and width 2.0m. If the tank is 4m high, what is the pressure at the middle of the tank?[g = 10ms-2]

1.0 x 104Nm-2

2.0 x 103Nm-2

1.5 x 103Nm-2

1.0 x 103Nm-2

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Question 29 Report

Two bodies X and Y are projected on the same horizontal plane, with the same initial speed but at angles 30 and 60 respectively to the horizontal. Neglecting air resistance, the ratio of the range of X to that of Y is

1:1

1:2

√3:1

√3

Answer Details

Range =

\frac{U^{2} s i n 2 θ}{g}

$\frac{R_{x}}{R_{y}}$ = $\frac{U_{x}^{2} s i n 60}{U_{y}^{2} s i n 120}$

sin60o = sin120o

$\frac{R_{x}}{R_{y}}$ = $\frac{1}{1}$

hence, = 1:1

Read lesson note on Motion (JAMB)

Motion

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Question 30 Report

If the load at the end of a sonometer wire is immersed in a bucket of water, the original fundamental frequency of the wire could be restored by

decrease the length of the wire

increasing the length of the wire

increasing the mass per unit length of the wire

changing the temperature of the wire

Temperature And Its Measurement

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Question 31 Report

The diagram above shows two wave forms P and Q at a particular instant in time. the two waves will interface

destructively to produce a wave of larger amplitude

destructively to produce a wave of smaller amplitude

constructively to produce a wave of larger amplitude

constructively to produce a wave of smaller amplitude

Sound Waves

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Question 32 Report

What is the total electrical energy consumed by using an electric cooker rated 1000W for 5 hrs?

5.3 x 103J

6.5 X 103J

1.8 X 107J

2.3 X 107J

Electrical Energy And Power

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Question 33 Report

An arrow of mass 0.1kg moving with a horizontal velocity of 15ms-1 is shot into a wooden block of mass 0.4kg lying at rest on a smooth horizontal surface. Their common velocity after impact is

15.0 ms-1

7.5 ms-1

3.8 ms-1

3.0 ms-1

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Question 34 Report

For a rough inclined plane on which lies a body of weight W, the angle θ in the diagram above becomes the angle of friction if

tan θ = coefficient of static friction

cos θ = coefficient of dynamic friction

sin θ = coefficient of sliding friction

sec θ = limiting frictional force

Friction

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Question 35 Report

A uniform light beam XZ is Hinged at X and kept in equilibrium by the forces T and F as shown in the diagram above. if XO = 20m and OY = 30cm, express T in terms of F

T =2√3/3

T= 2F

T = 5V3F/3

T = 5F

Equilibrium Of Forces

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Question 36 Report

The electromagnetic waves that are sensitive to temperature changes are

X-rays

Gamma-rays

Ultra-violet rays

Infra-red rays

Description Property Of Fields

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

Light Waves

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Question 37 Report

Light of velocity 3 x 108ms-1 is incident on a material of reflective of index n. If the velocity of light is reduced to 2.4 x 108ms-1 in the material, what is n?

2.33

2.25

1.33

1.25

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Question 38 Report

The power dissipated in an a.c. circuit with an r.m.s, current of 5A, r.m.s voltage of 10V and a phase angle of 60o is

25W

50W

120W

125W

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Question 39 Report

If $8 \times 10^{-2}\,\mathrm{J}$ of work is required to move $100\,\mu\mathrm{C}$ of charge from a point X to a point Y in an electrical circuit, the potential difference between X and Y is

4.0 x 102 v

4.0 x 104 v

8.0 x 102 v

Current Electricity

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Question 40 Report

Equal masses of copper and rubber are raised to the same temperature. After sometimes, the copper was observed to be at a lower temperature because

the specific heat capacity of copper is lower than that of rubber

copper expands more than rubber

the specific heat capacity of rubber is lower than that of copper

rubber expands more than copper

Scalars And Vectors

Temperature And Its Measurement

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Question 41 Report

A heating coil rated at 100W is used to boil off 0.5kg of boiling water. The time taken to boil off the water is [specific latent heat of vaporization of water = 2.3 x 106Jkg-1]

1.15 x 109 s

1.15 x 107 s

1.15 x 105 s

1.15 x 104 s

Heat Energy

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Question 42 Report

For what value of 6 are the forces in the diagram above in equilib4ruim

15∘

30∘

45∘

60∘

Equilibrium Of Forces

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Question 43 Report

In a meter bridge experiment, two resistor $2\Omega$ and $3\Omega$ occupy the left and right gaps respectively. Find the balance point from the left side of the bridge

20cm

40cm

60cm

80cm

Answer Details

Let the point be x

$\frac{2}{x}$ = $\frac{3}{100 - x}$