The inner diameter of a test tube can be measured accurately using a?
отговор
(D)
pair of vernier calipers
2
Two bodies have masses in the ratio 3:1. They experience forces which impart to them acceleration in the ratio 2:9 respectively. Find the ratio of forces the masses experienced.
отговор
(C)
2 : 3
3
Particles of mass 10\(^{-2}\)kg is fixed to the tip of a fan blade which rotates with angular velocity of 100rad-1. If the radius of the blade is 0.2m, the centripetal force is
отговор
(B)
20 N
4
A lead bullet of mass 0.05kg is fired with a velocity of 200ms\(^{-1}\) into a lead block of mass 0.95kg. Given that the lead block can move freely, the final kinetic energy after impact is
отговор
(A)
50 J
5
A ball of mass 0.1kg is thrown vertically upwards with a speed of 10ms-1 from the top of a tower 10m high. Neglecting air resistance, its total energy just before hitting the ground is
(take g = 10ms-2)
отговор
(C)
15 J
6
A car of mass 800kg attains a speed of 25m/s in 20 secs. The power developed in the engine is
отговор
(A)
1 . 25 x 104 W
7
When the brakes in a car are applied, the frictional force force on the tyres is
отговор
(D)
is an advantage because it is in the opposite direction of the motion of the car
8
If the stress on a wire is 10\(^7\)Nm\(^{-2}\) and the wire is stretched from its original length of 10.00 cm to 10.05 cm. The Young's modulus of the wire is
отговор
(D)
2 . 0 x 109 Nm-2
9
A solid weigh 10 .00 N in air, 6 N when fully immersed in water and 7 . 0 N when fully immersed in a liquid X. Calculate the relative density of the liquid, X.
отговор
(C)
3/4
10
When temperature of a liquid increases, its surface tension
отговор
(A)
Decreases
11
A gas at a volume of V0 in a container at pressure P0 is compressed to one-fifth of its volume. What will be its pressure if the magnitude of its original temperature T is constant?
отговор
(D)
5P0
12
A piece of substance of specific head capacity 450JKg-1K-1 falls through a vertical distance of 20m from rest. Calculate the rise in temperature of the substance on hitting the ground when all its energies are converted into heat. [g = 10ms-2]
отговор
(B)
4/9°C
13
I. A liquid boils when its saturated vapour pressure is equal to the external pressure
II. Dissolved substances in pure water lead to increase in the boiling point.
III. When the external pressure is increased, the boiling point increases.
IV. Dissolved substances in pure water decrease the boiling point.
Which combination of the above are peculiarities of the boiling point of a liquid?
отговор
(A)
I, II and III
14
The temperature gradient across a copper rod of thickness 0.02m, maintained at two temperature junctions of 20°C and 80°C respectively is
отговор
(B)
3.0 x 103Km-1
15
Calculate the mass of ice that would melt when 2kg of copper is quickly transferred from boiling water to a block of ice without heat loss.
Specific heat capacity of copper = 400JKg-1K-1
Latent heat of fusion of ice = 3.3 x 10\(^5\)JKg-1
отговор
(A)
8/33kg
16
The equation of a wave traveling along the positive x-direction is given by;
y = 0.25 x 10\(^{-3}\) sin (500t - 0.025x).
Determine the angular frequency of the wave motion.
отговор
(C)
5.00 x 102rad s-1
17
If a sound wave goes from a cold air region to a hot air region, its wavelength will
отговор
(A)
increase
18
The lowest note emitted by a stretched string has a frequency of 40Hz. How many overtones are there between 40hz and 180Hz?
отговор
(B)
3
19
A man stands 4m in front of a plane mirror. If the mirror is moved 1m towards the man, the distance between him and his new image is
отговор
(C)
6m
20
The inside portion of part of a hollow metal sphere of diameter 20cm is polished. The portion will therefore form a
отговор
(C)
convex mirror of focal length 5cm
21
The velocities of light in air and glass are 3.0 x 108ms-1 and 2.0 x 108ms-1 respectively. If the angle of refraction is 30°, the sine of the angle of incidence is
отговор
(D)
0.75
22
An astronomical telescope is said to be in normal adjustment when the
отговор
(D)
final image is at infinity
23
Which of the following electromagnetic waves is least energetic?
отговор
(A)
Infra-red rays
24
Steel is more suitable for permanent magnet than iron because the former
отговор
(D)
retains magnetism more than iron
25
Four cells each of e.m.f 1.5V and internal resistance of 4Ω are connected in parallel. What is the effective e.m.f. and internal resistance of the combination?
отговор
(D)
1.5V, 1Ω
26
A 3000W electric cooker is to be used on a 200V mains circuit. Which of the fuses below can be used safely with the cooker?
отговор
(D)
20A
27
A galvanometer has a resistance of 5Ω. By using a shunt wire of resistance 0.05Ω, the galvanometer could be converted to an ammeter capable of reading 2Amp. What is the current through the galvanometer?
отговор
(C)
20mA
28
In fleming's right-hand rule, the thumb, the forefinger and the middle finger if held mutually at right angles represent respectively, the
отговор
(A)
motion, the field and the induced current
29
At what frequency would a 10H inductor have a reactance of 2000Ω?
отговор
(C)
100/πHz
30
The core of an efficient transformer should consist of laminated pieces of metal in order to
отговор
(D)
reduce the heat produced by reducing the eddy current
31
Gamma rays are produced when
отговор
(B)
energy changes occur within the nucleus of atoms
32
What is the speed of a particle of mass 10-27kg whose wavelength is 10-8m.
[h = 6.63 x 10-34Js]
отговор
(B)
66.30ms-1
33
in a series R-L-C circuit at resonance, the voltages across the resistor and the inductor are 30V and 40V respectively, what is the voltage across the capacitor?
отговор
(B)
40V
34
In the Rutherford scattering experiment, a beam of alpha particles was fired at a thin gold film with some of the particles being considerably deflected. This shows that
отговор
(B)
the gold nucleus is positively charged and is concentrated in a tiny volume
35
2311Na + Proton → pqX + alpha particle
What are the values of p and q respectively in the equation above?
отговор
(C)
20 and 10
36
A semiconductor diode is used in rectifying alternating current into direct current mainly because it
отговор
(D)
allows current to flow only in one direction
37
if ∆x is the uncertainty in the measurement of the position of a particle along the x-axis and ∆Px is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is given as
отговор
(A)
∆x ∆Px ≥ h
38
If ∆x is the uncertainty in the measurement of the position of a particle along the x-axis and ∆Pa is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is given as
отговор
(A)
∆x ∆Px ≥ h
39
The diagram above shows the velocity-time graph of a vehicle. Its acceleration and retardation respectively are
отговор
(C)
4.0 ms-2, 2.0 ms-2
40
The figure above represents a frictionless pulley system in which a weight W is in equilibrium with a weight of 40N. Find the value of W
отговор
(D)
80.0N
41
The diagram above shows a solid figure with base PQ and center of gravity G on a inclined plane. Which of the following statements is correct
отговор
(A)
The solid will fall over if the vertical line through G lies outside the base
42
The diagram above shows a lift pump with valves at P and Q. During a downward stroke of the piston
отговор
(B)
P is open while Q is closed
43
In the J-tube above, Y and X are on the same horizontal level and 30cm3 of air is trapped above Y when the atmospheric pressure is 75cm Hg, calculate the volume of air trapped above Y when 15cm Hg is now poured into the limb above X
отговор
(B)
25 cm3
44
The diagram above represents a transverse electromagnetic wave travelling with speed 3.0 x 108ms-1. What is the frequency of the wave.
отговор
(D)
3.0 x 109Hz
45
The diagram above shows the prism arrangement in a
