JAMB UTME - Physics - 1987 | Green Bridge CBT

Tambaya 1 Rahoto

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

Duba Amsa

Tambaya 2 Rahoto

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

Bayanin Amsa

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

Karanta bayanin darasi akan Work, Energy And Power (WAEC)

Karanta bayanin darasi akan Equilibrium Of Forces (WAEC)

Work, Energy And Power

Equilibrium Of Forces

Duba Amsa

Tambaya 3 Rahoto

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

Bayanin Amsa

Q = mL + mc $θ$

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

= 674 360J

Karanta bayanin darasi akan Quantity Of Heat (JAMB)

Quantity Of Heat

Duba Amsa

Tambaya 4 Rahoto

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

Duba Amsa

Tambaya 5 Rahoto

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)

Duba Amsa

Tambaya 6 Rahoto

Which of the following instruments has a pure tone?

guitar

vibrating strings

tuning fork

siren

Sound Waves

Work, Energy And Power

Duba Amsa

Tambaya 7 Rahoto

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

Duba Amsa

Tambaya 8 Rahoto

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 .

126.50cm3

126.25cm3

126.00cm3

125.00cm3

Bayanin Amsa

Y = $\frac{V_{2} - V_{1}}{V_{1} \times θ}$

3 x 4 x 10-5 = $\frac{V_{2} - 125}{125 \times (120 - 20)}$

V2 = 126.50cm3

Karanta bayanin darasi akan Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

Duba Amsa

Tambaya 9 Rahoto

What type of reaction is represented by the following scheme?

\[ {}^{2}_{1}X + {}^{2}_{1}Y + {}^{3}_{2}Z + {}^{1}_{0}n + \text{energy} \]

Fusion reaction

Fission reaction

Chain reaction

Radioactive decay

Elementary Modern Physics

Duba Amsa

Tambaya 10 Rahoto

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

Duba Amsa

Tambaya 11 Rahoto

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

Bayanin Amsa

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

Karanta bayanin darasi akan Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

Duba Amsa

Tambaya 12 Rahoto

he lowest note emitted by a stretched string has a frequency of 40Hz. How many overtones are there between 40Hz and 150Hz?

1

2

3

4

Propagation Of Sound Waves

Duba Amsa

Tambaya 13 Rahoto

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

Duba Amsa

Tambaya 14 Rahoto

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)

Duba Amsa

Tambaya 15 Rahoto

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

Duba Amsa

Tambaya 16 Rahoto

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

Bayanin Amsa

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

Karanta bayanin darasi akan Light Energy (JAMB)

Karanta bayanin darasi akan Simple Harmonic Motion (WAEC)

Karanta bayanin darasi akan Quantity Of Heat (JAMB)

Light Energy

Simple Harmonic Motion

Quantity Of Heat

Duba Amsa

Tambaya 17 Rahoto

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 Electromagnetic Spectrum

Light Waves

Duba Amsa

Tambaya 18 Rahoto

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

Duba Amsa

Tambaya 19 Rahoto

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

Bayanin Amsa

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

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

= 212N

Karanta bayanin darasi akan Friction (JAMB)

Friction

Duba Amsa

Tambaya 20 Rahoto

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%

Bayanin Amsa

P.E = mgh = 1000m joules

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

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

= 20%

Karanta bayanin darasi akan Measurements And Units (JAMB)

Measurements And Units

Duba Amsa

Tambaya 21 Rahoto

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)

Duba Amsa

Tambaya 22 Rahoto

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

f

α

/

f

α \frac{1}{I^{2}}

f

α \sqrt{I}

f

1

Newton’s Laws Of Motion

Equilibrium Of Forces

Duba Amsa

Tambaya 23 Rahoto

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

Bayanin Amsa

V = F $λ$

= 2 x 0.3

= 0.6ms-1

Karanta bayanin darasi akan Production And Propagation Of Waves (WAEC)

Production And Propagation Of Waves

Duba Amsa

Tambaya 24 Rahoto

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

Bayanin Amsa

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

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

real depth = 1.33cm

Karanta bayanin darasi akan Refraction Of Light Through Plane And Curved Surfaces (JAMB)

Refraction Of Light Through Plane And Curved Surfaces

Duba Amsa

Tambaya 25 Rahoto

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

Bayanin Amsa

Thrust = force x time

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

270 = m(300 - 0)

m = 0.90kg

Karanta bayanin darasi akan Measurements And Units (JAMB)

Measurements And Units

Duba Amsa

Tambaya 26 Rahoto

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

Duba Amsa

Tambaya 27 Rahoto

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

five

four

three

two

Bayanin Amsa

n = $\frac{360}{θ}$ - 1

= 360 - 1

= 3 images

Karanta bayanin darasi akan Electrostatics (JAMB)

Electrostatics

Duba Amsa

Tambaya 28 Rahoto

Two capacitance of $6\,\mu\text{F}$ and $8\,\mu\text{F}$ are connected in series. What additional capacitance must be connected in series with this combination to give a total of $3\,\mu\text{F}$

3

μ

F

16

μ

F

24

μ

F

30

μ

F

Bayanin Amsa

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

therefore, C = 24 $μ$ F

Karanta bayanin darasi akan Capacitors (JAMB)

Capacitors

Duba Amsa

Tambaya 29 Rahoto

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

Bayanin Amsa

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

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

= 2.5ms-2

Karanta bayanin darasi akan Newton’s Laws Of Motion (WAEC)

Newton’s Laws Of Motion

Duba Amsa

Tambaya 30 Rahoto

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

Duba Amsa

Tambaya 31 Rahoto

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

Duba Amsa

Tambaya 32 Rahoto

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

Duba Amsa

Tambaya 33 Rahoto

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

Duba Amsa

Tambaya 34 Rahoto

A galvanometer of resistance $20\,\Omega$ 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

Bayanin Amsa

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

Rs = 2.22 $Ω$

Karanta bayanin darasi akan Electrostatics (JAMB)

Electrostatics

Duba Amsa

Tambaya 35 Rahoto

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

Bayanin Amsa

20cm .... 100oC

4.5cm .... $θ$

0cm ....0oC

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

$θ$ = 22.5oC

Karanta bayanin darasi akan Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

Duba Amsa

Tambaya 36 Rahoto

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

Duba Amsa

Tambaya 37 Rahoto

A load of 5N gives an extension of 0.56cm in a wire which obeys Hooke's law. What is the extension caused by a load of 20N?

1.12cm

2.14cm

2.24cm

2.52cm

Bayanin Amsa

$\frac{F_{1}}{e_{1}}$ = $\frac{F_{2}}{e_{2}}$

$\frac{5}{0.56}$ = $\frac{20}{e_{2}}$

e2 = 2.24cm

Karanta bayanin darasi akan Elasticity (JAMB)

Elasticity

Duba Amsa

Tambaya 38 Rahoto

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

Bayanin Amsa

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

R = $\sqrt{129}$

= 11.36km

Karanta bayanin darasi akan Scalars And Vectors (JAMB)

Karanta bayanin darasi akan Position, Distance And Displacement (WAEC)

Scalars And Vectors

Position, Distance And Displacement

Duba Amsa

Tambaya 39 Rahoto

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

Ns-1

Nms-1

Ns

Js-1

Bayanin Amsa

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

since, F = ma = kgms-1 = N

kgms-1 = Ns

Karanta bayanin darasi akan Measurements And Units (JAMB)

Measurements And Units

Duba Amsa

Tambaya 40 Rahoto

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

Duba Amsa

Tambaya 41 Rahoto

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