JAMB UTME - Physics - 1986 | Green Bridge CBT

Question 1 Report

A lens of focal length 12.0cm forms an upright image three times the size of a real object. The distance between the object and the images is

8.0cm

16.0cm

24.0cm

32.0cm

Answer Details

F = 12cm, V = 3u

F = $\frac{u v}{u + v}$

12 = $\frac{u \times 3 u}{u + 3 v}$

u = 16cm, and v = 48cm

therefore, distance between u and v

v = 48 - 16 = 32cm

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 2 Report

Which of the following assumptions is made in a simple pendulum experiment? the

suspending string is inextensible

bob has a finite size

bob has a definite mass

initial angle of oscillation must be large

Scalars And Vectors

Equilibrium Of Forces

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Question 3 Report

A heavy object is suspended from a string and lowered into water so that it is completely submerged. The object appears lighter because

the density of water is less than that of the object

the pressure is low just below the water surface

it experiences an upthrust

the tension in the string neutralizes part of the weight

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Question 4 Report

A constant force of magnitude F acts on an object of mass 0.04kg initially at rest at a point O. if the speed of the object when it has moved 50m from O is 500ms-1, what is the value of F?

0.4N

100.0N

250.0N

1000.0N

Answer Details

F = ma and V2 = U2 + 2aX

F = m $\frac{(V^{2} - U^{2})}{2 X}$

= 0.04 $\frac{(500^{2} - 0^{2})}{2 \times 50}$

F = 100N

Read lesson note on Current Electricity (JAMB)

Current Electricity

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Question 5 Report

In an experiment in which molten naphthalene is allowed to cool, the cooling curve in fig 5 was obtained, the temperature $80^\circ C$ is known as

cooling temperature

boiling point

melting point

vaporization point

Quantity Of Heat

Temperature And Its Measurement

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Question 6 Report

The angle between the magnetic meridian and the geographic meridian at a locality on the earth is the

longitude of the locality

angle of inclination at the locality

latitude of the locality

angle of declination of the locality

Electromagnetic Field (Part 2)

Introductory Electronics

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Question 7 Report

A rectangular tank contains water to a depth of 2m, if the base is 4m x 3m, calculate the force on the base (Density of water = 103kgm-3, g = 10ms-2)

1.4 x 102N

24 x 104N

2.0 x 104N

1.7 x 103N

Answer Details

Volume = 2 x 4 x 3 = 24m3

mass = V x D = 24 x 103

F = mg

= 24 x 103 x 10

= 24 x 104

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Question 8 Report

Which of the following is NOT a part of a d.c. electric motor?

Field-magnet

Armature

Commutator

Transformer

Electrostatics

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Question 9 Report

In fig 6, a ray of light in air strikes a glass plate at an angle of incidence 60 degrees, the reflected ray is observed to be perpendicular to the refracted ray, what is the refractive index of the glass

1.73

1.50

0.87

0.57

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Question 10 Report

Which of the following is common to evaporation and boiling? They

take place at any temperature

are surface phenomena

involve change of state

take place at a definite pressure

Change Of State

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Question 11 Report

In fig 9 the value of R is

3Ω

4Ω

5Ω

6Ω

Scalars And Vectors

Equilibrium Of Forces

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Question 12 Report

If the refractive index of glass is 1.5, what is the critical angle at the air-glass interface?

sin-1

\frac{1}{2}

sin-1

\frac{1}{2}

sin-1

\frac{3}{4}

sin-1

\frac{8}{9}

Answer Details

sin ic

\frac{1}{n}

=

\frac{1}{1 - 5}

i = sin-1 $\frac{1}{1 - 5}$

= sin-1 $\frac{10}{15}$

= sin-1 $\frac{2}{3}$

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

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

Reflection Of Light At Plane And Curved Surfaces

Refraction Of Light Through Plane And Curved Surfaces

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Question 13 Report

A pencil is placed vertically between a concave mirror and its focal point. The image of the pencil in the mirror will be

real, inverted and diminished

virtual, inverted and enlarged

real, erect and enlarged

virtual, erect and enlarged

Electrostatics

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Question 14 Report

Which of the following is a derived unit?

Kilogramme

Meter

Kelvin

Newton

Answer Details

Force is a derived quantity, it's unit is a derived unit

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

Fundamental And Derived Quantities And Units

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Question 15 Report

Fig 4 represents a block-and-tackle pulley system on which an effort of W newtons supports a load of 120.0N if the efficiency of the system is 40% then the value of W is

28.0N

48.0N

50.0N

288.0N

Simple Machines

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Question 16 Report

A gas occupies a volume of 300cm3at a temperature of 27oC. What is its volume at 54oC, when the pressure is constant?

150cm3

273cm3

327cm3

600cm3

Answer Details

\frac{V_{1}}{T_{1}}

=

\frac{V_{2}}{T_{2}}

$\frac{300}{27 + 273}$ = $\frac{V_{2}}{54 + 273}$

V2 = 327cm3

Read lesson note on Quantity Of Heat (JAMB)

Quantity Of Heat

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Question 17 Report

The mode of heat transfer which does not require a material medium is

conduction

radiation

convection

propagation

Heat Transfer

Conduction Of Electricity Through

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Question 18 Report

Which of the following is in a neutral equilibrium?

a heavy weight suspended on a string

a cone resting on its slant edge

a heavy-based table lamp

the beam of a balance in use

Work, Energy & Power

Equilibrium Of Forces

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Question 19 Report

The expansion of solids can be considered a disadvantage in the

balance wheel of a watch

fitting of wheels on rims

fire alarm

thermostat

Thermal Expansion

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Question 20 Report

The wavelength of ultraviolet radiation is 400nm. If the speed of light in air is 3 x 108ms-1, then the frequency of the ultraviolet radiation is

1.3 x 1015Hz

7.5 x 105Hz

1.2 x 1011Hz

7.5 x 1014Hz

Answer Details

F =

\frac{V}{λ}

= $\frac{3 \times 10^{8}}{400 \times 10^{9}}$

= 75 x 1015Hz

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 21 Report

When two objects P and Q are supplied with the same quantity of heat, the temperature change in P is observed to be twice that of Q. The ratio of the specific heat capacity of P to Q is

1 : 4

4 : 1

1 : 1

2 : 1

Answer Details

θ

p = 2

θ

q

mq = 2mp

Cp X mp X $θ$ p = Cq x mq x $θ$ q

$\frac{C_{p} m_{q} θ q}{C_{q} m_{p} θ q}$ = $\frac{θ q \times 2 m p}{2 θ q m p}$

$\frac{C_{p}}{C q}$ = $\frac{2}{2}$

Read lesson note on Quantity Of Heat (JAMB)

Quantity Of Heat

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Question 22 Report

The specific latent heat of fusion of lead is the amount of heat required to

melt lead at its melting point

heat a unit mass of lead through 1oC

change the state of a unit mass of lead at its melting point

change the state of a unit mass of lead at its boiling point

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Question 23 Report

A 1000kg elevator is descending vertically with an acceleration of 1.0ms-2, if the acceleration due to gravity is 10ms-2, the tension in the suspending cable is

1.0N

10.0N

9000.0N

11 000N

Answer Details

The elevator is descending so the weight acts in line with the acceleration which is downwards. So according to Newton's law,
mg(weight) -R (tension/reaction) = ma

Read lesson note on Motion (JAMB)

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

Read lesson note on Equilibrium Of Forces (WAEC)

Motion

Position, Distance And Displacement

Equilibrium Of Forces

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Question 24 Report

In fig 3, three forces F1, F2, and F3 acting at O are in equilibrium. If the magnitude of F1 is 10N,and the magnitude of F2 is 5N, find the magnitude of F3

26.4N

15.0N

13.2N

10.0N

Equilibrium Of Forces

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Question 25 Report

In which of the following arrangements is the wavelength in an increasing order?

Gamma rays, infra-red rays, x-rays, radiowaves

Gamma rays, x-rays, infra-red ray, radiowaves

Radiowaves, x-rays, gamma ray, infra-red rays

Infra-red rays, radiowaves, x-rays, gamma rays

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

Wave-particle Paradox

Structure Of The Nucleus

Types Of Waves

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Question 26 Report

The vibration of an air column produces the sound in the

piano

guiter

flute

school handbell

Current Electricity

Sound Waves

Conduction Of Electricity Through

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Question 27 Report

A man clapping his hands at regular intervals observes that the echo of a clap coincides with the next clap. If the reflecting cliff is 160m away and the speed of sound is 320ms-1, what is the frequency of the clapping?

1 Hz

2Hz

4Hz

8Hz

Answer Details

Total distance = 2 x 160 = 320cm

Total time = $\frac{320}{320}$ = 1s

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

= 1Hz

Read lesson note on Current Electricity (JAMB)

Current Electricity

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Question 28 Report

A dentist obtains a linear magnification of 4 of a hole in a tooth by placing a concave mirror at a distance, of 2.0cm from the tooth. The radius of Curvature of the mirror is

5.3cm

3.2cm

2.7cm

1.6cm

Answer Details

v = 4u, if u = 2cm, v = 8cm

F = $\frac{u v}{u + v}$

= $\frac{2 \times 8}{2 + 8}$

= 1.6cm

r = 2F

= 2 x 1.6

= 3.2cm

Read lesson note on Measurements And Units (JAMB)

Measurements And Units

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Question 29 Report

A uniform meter rule QR is balanced on a knife edge which is 55cm from R, when a mass of 10g is hung at P as shown above, the mass of the meter rule is (Note that QP is 10cm)

550g

350g

70g

35g

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Question 30 Report

If the fig above E is an accumulator with negligible internal resistance. and the EMF 9.0V, The the total current is

0.3A

0.8A

1.0A

1.8A

Current Electricity

Electric Cells

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Question 31 Report

A wave of frequency 10Hz forms a stationary wave pattern in a medium where the velocity is 20cms-1. The distance between adjacent nodes is

1.0cm

1.5cm

2.0cm

5.0cm

Answer Details

λ

=

\frac{v}{f}

= $\frac{20}{10}$

= 2cm ; distance between adjacent nodes

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Question 32 Report

Which of the following is true of sounds?

sound travels faster in air at 20oC than at 30oC

the frequency of a given sound wave changes when it crosses the boundary seperating two media

the wavelength of a given sound wave in air decreases as the temperature increases

sound waves cannot be reflected

Current Electricity

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Question 33 Report

A ball is thrown vertically into the air with an initial velocity u. What is the greatest height reached?

u2g

3u²

2g

u²

g

\frac{u^{2}}{2 g}

Answer Details

Using V2 = U2 - 2gS

V = 0ms-1 at greatest height

S = $\frac{u^{2}}{2 g}$

Read lesson note on Gravitational Field (JAMB)

Gravitational Field

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Question 34 Report

Which of the following represents the correct precision if the length of a piece of wire is measured with a meter rule?

35mm

35.0mm

35.00mm

35.01mm

Measurements And Units

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Question 35 Report

When a box of mass 45kg, is given an initial speed of 5ms-1 it slides along a horizontal floor a distance of 3m before coming to a rest. what is the coefficient of kinetic friction between the box and the floor? (G = 10ms-2)

5

6

5

12

1

3

2

3

Work, Energy & Power

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Question 36 Report

Mercury is suitable as a barometric fluid because it

expands uniformly

is opaque

is several times denser than water

is a good conductor of heat

Pressure

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Question 37 Report

Fig 1 is a graph of force against extension for a spiral spring, the force constant of the spring is given by the

slope of the linear prtion of the graph

length of the linear portion of the graph

area under the linear portion of the graph

area under the entire graph

Elasticity

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Question 38 Report

Two objects, one having three times the mass of the other, are dropped at the same time from a tall building. When they are above the ground, the two objects will have the same

Momentum

Kinetic energy

Potential energy

Acceleration