JAMB - Physics (2009)

1
I. Diameter of a small ball bearing.
II. Thickness of a pieces of paper.
III. Diameter of a measuring cylinder.
IV. Length of a piece of wire.
Which of the above can be measured using a micrometer screw gauge?
Answer
(B)
I and II only
2
What is the acceleration between two points on a velocity time graph which has coordinates
(10s, 15 ms-1)
and (20 s, 35 ms-1)?
Answer
(D)
2.00 ms-2
3
A bullet fired vertically upward from a gun held 2.0 m above the ground reaches its maximum height in 4.0s. calculate its initial velocity.


[g = 10ms-2]
Answer
(C)
40 ms-1
4
I. The motion of the tyres of a moving car.
II. The motion of a loaded test tube oscillated
vertically.
III. The beating of the heart.
IV. A stone tied to a string and whirled round.
V. The motion of the pistons in a gasoline engine.
Which of the motions above is simple harmonic?
Answer
(B)
II, III and V only
5
If a cage containing a truck of coal weighing 750 kg is raised to a height of 90 m in a minute, what is the total power expended?


[g = 10 ms2]
Answer
(C)
11.25 kw
6
An object of mass 80 kg is pulled on a horizontal rough ground by a force of 500 N. Find the coefficient of static friction.


[g = 10 ms-2]
Answer
(D)
0.6
7
If a heavy barrel is rolled up a plane inclined at 30° to the horizontal. its velocity ratio will be?
Answer
(D)
2.0
8
I. Density of the liquid.
II. Acceleration due to gravity.
III. Type of container of the liquid.
IV. The constituents of the liquid.
which of the above conditions will NOT affect the pressure of fluid?
Answer
(C)
III and IV only
9
If a load of mass 10N stretched a cord by 1.2cm, what is the total work done?
Answer
(A)
6.0 x 10-2J
10
A plastic sphere floats in water with 50% of its volume submerged. if it floats in glycerine with 40% of its volume submerged,the density of the glycerine is?
Answer
(B)
1250 kgm-3
11
The thermometer whose reading is indicated by a change in color of its thermometric property is the?
Answer
(D)
optical pyrometer
12
At 4°c, the volume of a fixed mass of water is?
Answer
(B)
minimum
13
An electric heater rated 220v, 1000 w is immersed into a bucket full of water, calculate the mass of water if the temperature changes from 30°c to 100°c and the current flows for 300seconds.

[specific heat capacity of water = 4200 jkg-1 K-1]
Answer
(C)
1.02 kg
14
If the pressure of the vapor on top of an enclosed liquid is equal to the atmospheric pressure, what will be the temperature of the liquid enclosed?
Answer
(B)
boiling point
15
A heating coil rated 1000 W is used to boil off completely 2 kg of boiling water. The time required to boil  the water is?

[Special latent heat of Vaporization of water = 2.3 x 10\(^6\) Jkg-1]
Answer
(D)
4.6 x 103s
16
It is observed that water will wet a clean glass because the?
Answer
(D)
adhesion of water molecules is stronger than the cohesion of water molecules
17
A man standing 2 m from a charcoal fire is warmed mainly by?
Answer
(B)
radiation
18
Metal cables are used as telephone wires because?
Answer
(D)
the speed of sound in them is very high
19
Musical instruments playing the same note can be distinguished from one another owing to the differences in their?
Answer
(A)
quality
20
I. Moon.
II. Sun.
III.street light.
IV. stars.
Which of these are natural sources of light?
Answer
(D)
II and IV only
21
An object is placed 5 cm from the pole of a concave mirror. if the focal length of the mirror is 10 cm. what is the image distance?
Answer
(C)
10 cm behind the mirror
22
Calculate the position of an object placed in front of a convex mirror having focal length of 12 cm such that an image is formed 6 cm away from the mirror
Answer
(C)
12.0 cm
23
If the refractive index of crown glass is 1.51, its critical angle is?
Answer
(C)
41.5°
24
When light passes through two media x and y of refraction indices 1.51 and 1.33 respectively, the speed of light in
Answer
(D)
y is higher than in x
25
The ability of the human eye to focus object on the retina is referred to as the power of?
Answer
(C)
accomodation
26
Which of the following is a secondary colour
Answer
(B)
orange
27
If negative charges are induced on an electroscope and a positively charged rod is brought near the cap of the electroscope, the leaves will?
Answer
(A)
close up
28
An electric lamp marked 240v, 60 W is left to operate for an hour. How much energy is generated by the filament?
Answer
(D)
2.16 x 105J
29
A band of 500 rectangular loops of wire of area 20 cm by 20 cm, encloses a region of magnetic field which charges from 1.0T to 0.4T within 5 seconds, calculate the induced e.m.f.
Answer
(D)
2.40 v
30
Cancerous cells can be destroyed by?
Answer
(C)
x - rays
31
If the decay constant of a radioactive substance is 0.231s-\(^1\), the half-life is?
Answer
(A)
3.00 s
32
A piece of radioactive material contains 10\(^{20}\) atoms.
If the half life of the material is 20 seconds, the number of disintegration in the first second is?
Answer
(A)
3.47 x 1018
33
Thermionic emission is the process whereby?
Answer
(D)
electrons leave a hot element
34
Which of the following can conduct electricity owing to the presence of free mobile electrons?
Answer
(D)
copper
35
When a pentavalent impurity is added to a pure semiconductor, it becomes?
Answer
(B)
an n-type semiconductor
36
The value of x, y and z respectively in the expression M\(^x\) L\(^y\)T \(^z\) for the universal gravitational constant G are?
Answer
(B)
-1, 3, -2
37
An air craft attempt to fly due north at 100 kmh-1. If the wind blows against it from east to west at 60 kmh-1, its resultant velocity is?
Answer
(C)
117 kmh-1, N31oW
38
A car accelerate uniformly from rest at 4 ms-2. How far will it travel in the fifth complete second?
Answer
(D)
18 m
39
A body of mass 12kg traveling at 4.2ms-1 collides with a second body of mass 18kg at rest. Calculate their common velocity if the two bodies coalesce after collision?
Answer
(D)
1.7 ms-1
40
The terminal velocity of a ball-bearing falling through a viscous fluid is reached when the?
Answer
(D)
velocity is uniform
41
The pressure of two moles of an ideal gas at a temperature of 27oC and volume 10-2m3 is?
[R = 8.313 J mol-1K-1]
Answer
(A)
4.99 x 105 Nm-2
42

The wave phenomenon demonstrated in the diagram above is?

Answer
(C)
diffraction
43

The diagram above represents the graph of the force F applied in stretching a spiral spring against the corresponding extension (X). The force constant of the spring is?

Answer
(A)
20 Nm-1
44
If a light wave has a wavelength of 500nm in air what is the frequency of the wave?
[c = 3 x 10\(^8\) ms-1]
Answer
(B)
6.0 x 1014 Hz
45

Calculate the e.m.f of the cell in the above circuit if its internal resistance is negligible

Answer
(B)
8 V