JAMB UTME - Physics - 1987 | Green Bridge CBT

Vraag 1 Verslag

Which of the following statements supports the assumption that light travels in straight lines?

light can be diffracted

a source of light produces distinct shadows of opaque objects

a source of light produces interference patterns on a suitably placed screen

light can be reflected

Light Energy

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Vraag 2 Verslag

If an object is placed in front of two mirrors inclined at 90o, how many images will be formed?

five

four

three

two

Antwoorddetails

n = $\frac{360}{θ}$ - 1

= 360 - 1

= 3 images

Lees lesnotitie op Electrostatics (JAMB)

Electrostatics

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Vraag 3 Verslag

In the figure above, M and N are insulated metal spheres in contact. A negatively charged ebonite rod P is I brought near M. When M and N are Separated and the rod is taken away, which of the following statements is correct

both M and N have acquired negative charges

both M and N have acquired positive charges

M has acquired negative charge and N positive charge

N has acquired negative charge and M positive charge

Electrostatics

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Vraag 4 Verslag

A man walks 8km north and then 5km in a direction 60o east of north. Find the distance from his starting point

11.36km

12.36km

13.00km

14.36km

Antwoorddetails

R = $\sqrt{5^{2} + 8^{2} - 2 \times 5 \times 8 \times c o s 120^{o}}$

R = $\sqrt{129}$

= 11.36km

Lees lesnotitie op Scalars And Vectors (JAMB)

Lees lesnotitie op Position, Distance And Displacement (WAEC)

Scalars And Vectors

Position, Distance And Displacement

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Vraag 5 Verslag

A radioactive sample initially contains N atoms. After three half-lives the number of atoms that have disintegrated is

N

8

3N

8

5N

8

7N

8

Antwoorddetails

N $\to$ $\frac{N}{2}$ $\to$ $\frac{N}{4}$ $\to$ $\frac{N}{8}$

Lees lesnotitie op Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

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Vraag 6 Verslag

Which of the following units is equivalent to kgms-1?

Ns-1

Nms-1

Ns

Js-1

Antwoorddetails

kgms-1 = $\frac{m a s s}{d i s t a n c e}$

since, F = ma = kgms-1 = N

kgms-1 = Ns

Lees lesnotitie op Measurements And Units (JAMB)

Measurements And Units

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Vraag 7 Verslag

Which of the following statements is TRUE of photoelectric effect?

it cannot occur in liquids

the energy of the emitted electrons is independent of the work function of the surface

the energy of the emitted electron depends on the wavelength of the incident light

the greater the intensity of the incuident light, the greater the incident of the emitted electron

Structure Of The Atom (Nigeria Only)

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Vraag 8 Verslag

A wave has a frequency of 2Hz and a wavelength of 30cm. The velocity of the wave is

60.0ms-1

6.0ms-1

1.5ms-1

0.6ms-1

Antwoorddetails

V = F $λ$

= 2 x 0.3

= 0.6ms-1

Lees lesnotitie op Production And Propagation Of Waves (WAEC)

Production And Propagation Of Waves

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Vraag 9 Verslag

Hot water is added to three times its mass of water at 10oC and the resultant temperature is 20oC. What is the initial temperature of the hot water?

100oC

80oC

50oC

40oC

Antwoorddetails

Heat loss = heat gained

mh x ch x $θ$ h = mc x cc x $θ$ c

mh x ch x ( $θ$ - 20) = mc x cc x (20 - 10)

ch = cc ; mc = 3mh

therefore, $θ$ = 50oC

Lees lesnotitie op Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

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Vraag 10 Verslag

A galvanometer of resistance 20 $Ω$ is to be provided with a shunt that $\frac{1}{10}$ of the whole current in a circuit passes through the galvanometer. The resistance of the shunt is

2.00

Ω

2.22

Ω

18.00

Ω

18.22

Ω

Antwoorddetails

$\frac{1}{10}$ I x 20 = $\frac{9}{10}$ I x Rs

Rs = 2.22 $Ω$

Lees lesnotitie op Electrostatics (JAMB)

Electrostatics

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Vraag 11 Verslag

22,000J of heat is required to raise the temperature of 1.5kg of paraffin from 20oC to 30oC. Calculate the specific heat capacity of paraffin.

1466Jkg-1oC-1

2933Jkg-1oC-1

4400Jkg-1oC-1

5866Jkg-1oC-1

Heat Energy

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Vraag 12 Verslag

The direction of the magnetic field at a point in the vicinity of a bar magnet is

always towards the north pole of the magnet

always away from the south pole of the magnet

along the line joining the point to the neutral point

in the direction the north pole of a compass needle would point

Magnetic Field (Part 1)

Electromagnetic Field (Part 2)

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Vraag 13 Verslag

Two capacitance of 6 $μ$ F and 8 $μ$ F are connected in series. What additional capacitance must be connected in series with this combination to give a total of 3 $μ$ F

3

μ

F

16

μ

F

24

μ

F

30

μ

F

Antwoorddetails

3 = $\frac{6 \times 8 \times c}{(6 \times 8) + (6 \times c) + (8 \times c}$

therefore, C = 24 $μ$ F

Lees lesnotitie op Capacitors (JAMB)

Capacitors

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Vraag 14 Verslag

When two parallel wires carry currents in opposite directions, the force on either wire is

away from the other wire

zero, because the currents cancel each other

twice as much as when the currents are in the same direction

towards the other wire

Newton’s Laws Of Motion

Equilibrium Of Forces

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Vraag 15 Verslag

When a transformer has more secondary windings than primary windings, it

has a smaller secondary current

has a greater power output

is a step-down transformer

increases the total energy output

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Vraag 16 Verslag

If the angle of declination in a place is 10oE, calculate the true geographic bearing if the compass reads N40oE

N50oE

N40oE

N30oE

N25oE

Speed And Velocity

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Vraag 17 Verslag

Four lenses are being considered for use as a microscope objective. Which of the following focal lengths is most suitable?

-5mm

+5mm

-5cm

+5cm

Electromagnetic Waves: Types Of Radiation In Elect

Light Waves

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Vraag 18 Verslag

An object 3.0cm high is placed 60.0cm from a converging lens whose focal length is 20.0cm. Calculate the size of the image formed

0.5cm

1.5cm

2.0cm

6.0cm

Antwoorddetails

F = $\frac{U V}{U + V}$

20 = $\frac{60 \times V}{60 + V}$

V = 30cm

similarly, $\frac{U}{V}$ = $\frac{height of object}{height of image}$

$\frac{60}{30}$ = $\frac{3}{h}$

h = 1.5cm

Lees lesnotitie op Light (JAMB)

Lees lesnotitie op Measurements And Units (JAMB)

Light

Measurements And Units

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Vraag 19 Verslag

A cube of side 10cm and mass 0.5kg floats in a liquid with only $\frac{1}{5}$ of its height above the liquid surface. What is the relative density of the liquid?

0.125cm-1

0.250gcm-1

0.625cm-1

2.500cm-1

Antwoorddetails

Height below liquid = 1 - $\frac{1}{5}$ = $\frac{4}{5}$

volume of cube = 103cm3

volume of liquid displaced = $\frac{4}{5}$ x 1000

= 800cm3

density of liquid displaced;

= $\frac{500}{800}$

= 0.625cm-1

Lees lesnotitie op Light Energy (JAMB)

Lees lesnotitie op Simple Harmonic Motion (WAEC)

Lees lesnotitie op Quantity Of Heat (JAMB)

Light Energy

Simple Harmonic Motion

Quantity Of Heat

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Vraag 20 Verslag

In which of the following are the substance arranged in descending order of their thermal conductivities?

copper, steel, glass

steel, copper, glass

steel, glass, copper

copper, glass, steel

Heat Transfer

Fluid At Rest

Gravitational Field

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Vraag 21 Verslag

he coefficient of static friction between a 40kg crate and concrete surface is 0.25. Find the magnitude of the minimum force needed to keep the crate stationary on the concrete base inclined at 45o to the horizontal. [G = 10ms-1]

400N

300N

283N

212N

Antwoorddetails

momentum force = R5n $θ$ - $μ$ Rcos $θ$

Fm = (40 x 10 x sin 45) - (40 x 10 x 0.25 x cos 45)

= 212N

Lees lesnotitie op Friction (JAMB)

Friction

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Vraag 22 Verslag

As a result of air at the top of a barometer, the height of the mercury column is 73.5cm when it should be 75.0cm; the volume of the space above the mercury is 8.0cm3. Calculate the correct barometer height when the barometer reads 74.0cm and the volume of the space above the mercury is 6.0cm3.

72.0cm

74.5cm

75.1cm

76.0cm

Pressure

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Vraag 23 Verslag

The fig above represents the main sequence of energy conversion at Kainji dam. What is the efficiency of the system?

Q1/Q2

E/Q1

E/(Q1-Q2)

E/(Q1+Q2)

Heat Energy

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Vraag 24 Verslag

Which of the following instruments has a pure tone?

guitar

vibrating strings

tuning fork

siren

Sound Waves

Work, Energy And Power

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Vraag 25 Verslag

A constant force of 40N acting on a body initially at rest gives an acceleration of 0.1ms-2 for 4s. Calculate the work done by the force

8J

10J

32J

160J

Antwoorddetails

X = ut + $\frac{1}{2}$ at2

= (0 x 4) + ( $\frac{1}{2}$ x 0.1 x 4 x 4)

= 0.8m

workdone = force x distance

= 40 x 0.8

= 32J

Lees lesnotitie op Work, Energy And Power (WAEC)

Lees lesnotitie op Equilibrium Of Forces (WAEC)

Work, Energy And Power

Equilibrium Of Forces

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Vraag 26 Verslag

A 50kg block is dropped from a point 10cm above as shown in the fig above. if the force constant of the spring is 4.0 x 104Nm-1, find the maximum compression of the spring [g = 10ms-2]

1.25m

0.50m

0.25m

0.05m

Equilibrium Of Forces

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Vraag 27 Verslag

A current of 0.5A flows through a resistor when connected to a 40-V battery. How much energy is dissipated in 2 minutes?

1200J

1500J

2400J

96000J

Current Electricity

Work, Energy And Power

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Vraag 28 Verslag

A jet engine develops a thrust of 270Ns when the velocity of the exhaust gases relative to the engine is 300ms-1. What is the mass of the material ejected per second?

81.00kg

9.00kg

0.90kg

0.09kg

Antwoorddetails

Thrust = force x time

thrust = $\frac{m (v - u)}{t}$ x $\frac{t}{1}$

270 = m(300 - 0)

m = 0.90kg

Lees lesnotitie op Measurements And Units (JAMB)

Measurements And Units

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Vraag 29 Verslag

Calculate the amount of heat required to convert 2kg of ice at 2oC to water at 0oC. [specific heat capacity of ice = 2090Jkg-1oC-1, specific latent heat of fusion of ice = 333kJkg-1]

666J

8360J

666 000J

674 360J

Antwoorddetails

Q = mL + mc $θ$

= (2 x 333000) + (2 x 2090 x 2)

= 674 360J

Lees lesnotitie op Quantity Of Heat (JAMB)

Quantity Of Heat

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Vraag 30 Verslag

If a beaker is filled with water it is observed that the surface of the water is not horizontal at the glass-water interface. This behavior is due to

friction

viscosity

surface tension

evaporation

Friction

Temperature And Its Measurement

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Vraag 31 Verslag

A ray of light is incident at an angle of 30o on one top surface of a parallel-sided glass block of refractive index 1.5. The ray finally emerges from the lower surface. What is the angular deviation of the emergent ray?

60o

39o

28o

0o

Reflection Of Light At Plane And Curved Surfaces

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Vraag 32 Verslag

The distance between the fixed points of a centigrade thermometer is 20cm. What is the temperature when the mercury level is 4.5cm above the lower mark?

22.5oC

29.0oC

90.0oC

100.0oC

Antwoorddetails

20cm .... 100oC

4.5cm .... $θ$

0cm ....0oC

$\frac{4.5 - 0}{20 - 0}$ = $\frac{0 - 0}{100 - 0}$

$θ$ = 22.5oC

Lees lesnotitie op Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

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Vraag 33 Verslag

When the length I of a piece of wire under constant tension is varied, the relationship of the frequency of the vibration f $α$ / is

f

α

/

f

α \frac{1}{I^{2}}

f

α \sqrt{I}

f

1

Newton’s Laws Of Motion

Equilibrium Of Forces

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Vraag 34 Verslag

In the above, a voltage V is applied across the terminals P and Q. The voltage across the 1 ohm resistor is

V/8

V/4

V/3

V/2

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Vraag 35 Verslag

An elevator of mass 4800kg is supported by a cable which can safely withstand a maximum tension of 60 000N. The maximum upward acceleration the elevator can have is

2.5ms-2

5.0ms-2

7.5ms-2

10.0ms-2

Antwoorddetails

a = $\frac{F}{m}$

= $\frac{60000 - (4800 \times 10)}{4800}$

= 2.5ms-2

Lees lesnotitie op Newton’s Laws Of Motion (WAEC)

Newton’s Laws Of Motion

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Vraag 36 Verslag

Which of the following phenomena explains the fact that a house whose roof is coated with white paint will be cooler in the hot season than one coated with black paint ?

conduction

convection

refraction

reflection

Pressure

Simple A.C Circuits

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Vraag 37 Verslag

A pool of water appears to be 1.0m deep when viewed vertically from above. If the refractive index of water is 1.33, what is the actual depth of the pool?

0.750m

1.013m

1.330m

13.3000m

Antwoorddetails

n = $\frac{real depth}{apparent depth}$

1.33 = $\frac{real depth}{1}$

real depth = 1.33cm

Lees lesnotitie op Refraction Of Light Through At Plane And Curved (JAMB)

Refraction Of Light Through At Plane And Curved

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Vraag 38 Verslag

The velocity time graph above describes the motion of a particle between two points P and Q. What is the distance between P and Q?

17.0m

18.0m

22.5m

30.0m

Motion

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Vraag 39 Verslag

A body rolls down a slope from a height of 100m. its velocity at the foot of the slope is 20ms-1. What percentage of its initial potential energy is converted into kinetic energy? [g = 10ms-1]

40%

35%

20%

15%

Antwoorddetails

P.E = mgh = 1000m joules

K.E = $\frac{1}{2}$ mv2 = 200m joules

%converted = $\frac{200 m}{1000 m}$ x 100

= 20%

Lees lesnotitie op Measurements And Units (JAMB)

Measurements And Units

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Vraag 40 Verslag

What type of reaction is represented by the following scheme? $_{1}^{2} X$ + $_{1}^{2} Y$ + $_{2}^{3} Z$ + $_{0}^{1} n$ + energy

Fusion reaction

Fission reaction

Chain reaction

Radioactive decay

Elementary Modern Physics

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Vraag 41 Verslag

The fig above shows two connected bodies of masses M1 and M2 in equilibrium under gravity. The tension in the upper string is

(m1-m2)g

m1g

m2g

(m1+m2)g

Equilibrium Of Forces

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Vraag 42 Verslag

The vacuum in a thermos flask helps to reduce heat transfer by?

convection and radiation

convection and conduction

conduction and radiation

radiation only

Heat Transfer

Temperature And Its Measurement

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Vraag 43 Verslag

The mechanical advantage (MA) of an inclined plane depends on

its length

its height

the product of its length and height

the ratio of its length to its height

Bekijk antwoord

Vraag 44 Verslag

Isotopes are nuclei which have

the same number of nuetrons and electrons

equal number of electrons and protons

the same atomic number but different number of neutrons

the same number of total particles

Structure Of The Atom (Nigeria Only)

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Vraag 45 Verslag

The length of a side of a metallic cube at 20oC is 5.0cm. Given that the linear expansivity of the metal is 4.0 x 10-5k-1, find the volume of the cube at 120oC .