The unit of moment of a couple can be expressed in?
回答
(C)
N m
2
A gramophone record takes 5s to reach its constant angular velocity of 4\(\pi\) rads-1 from rest. Find its constant angular acceleration.
回答
(B)
0.8\(\pi\) rads-2
3
A car of mass 1500 kg goes round a circular curve of radius 50m at a speed of 40 ms-1. The magnitude of the centripetal force on the car is ?
回答
(A)
4.8 x 104 N
4
Two spheres of masses 5.0 kg and 10.0 kg are 0.3 m apart. Calculate the force of attraction between them?
[G = 6.67 X 10-11 Nm2 Kg\(^{-2}\)]
回答
(B)
3.71 x 10-8 N
5
A machine has a velocity ratio of 4. if it requires 800 N to overcome a load of 1600 N,what is the efficiency of the machine?
回答
(B)
50%
6
A reservoir 500 m deep is filled with a fluid of density 850 kgm-3. If the atmospheric pressure is 1.05 x 105 Nm-2, the pressure at the bottom of the reservoir is.
[g = 10ms-2]
回答
(B)
4.36 x 106 Nm-2
7
A piece of iron weights 250 N in air and 200 N in a liquid of density 1000 kgm-3. the volume of the iron is?
回答
(A)
5.0 x 10-3 m-3
8
A clinical thermometer is different from other mercury in glass thermometers owing to
回答
(A)
the constriction on its stem
9
I. Use a liquid with a high melting point.
II. use a liquid of high volume expansivity.
III. use a capillary tube of large diameter.
which of the above best describes how the sensitivity of a liquid-in-glass thermometer can be enhanced?
回答
(B)
II. only
10
2 kg of water is heated with a heating coil which draws 3.5 A from a 200 V mains for 2 minutes. what is the increase in temperature of the water?
[specific heat capacity of water = 4200 jkg -1k-1]
回答
(D)
10°
11
I. Increase the melting point of the liquid.
II. Increase the boiling point of the liquid.
III. Decrease the melting point of the liquid.
IV. Decrease the boiling point of the liquid.
which of the statement above about the effect on increase in pressure in a liquid are correct?
回答
(C)
II and III only
12
I. Mass
II. Density
III. Temperature
IV. Nature of substance
which of the above affect diffusion?
回答
(D)
I, II, III and IV
13
The blade of a hoe feel colder to touch in the morning than the wooden handle because the
回答
(C)
blade is a better conductor of heat than the handle
14
I. They should be identical
II. They should originate from the same source.
III. They should be coherent.
IV. They should be monochromatic.
from the statements above, the conditions for two waves to interfere are?
回答
(B)
I, III and IV only
15
In a large telecommunications auditorium, perforated absorbent materials are used to line the ceiling so as to
回答
(D)
reduce the reverberation of sound in the hall
16
The phenomenon of light bending round an obstacle is?
回答
(A)
diffraction
17
The instrument used by designers to obtain different color pattern is called?
回答
(D)
kaleidoscope
18
A glass plate 0.9cm thick has a reflective index of 1.50. how long does it take for a pulse of light to pass through the plate?
[c = 3.0 x 10\(^8\) ms-1]
回答
(A)
4.5 x 10-11s
19
When an object is placed between the principal focus and the optical center of a convex lens, it could be used as a?
回答
(A)
Simple microscope
20
The production of pure spectrum could easily be achieved using a?
回答
(B)
triangular prism with two convex lens
21
A charge 50 µc has electric field strength of 360 NC-1 at a certain point. The electric field strength due to another charge 120 µc kept at the same distance apart and in the same medium is?
回答
(A)
864 NC-1
22
The energy E of a photon and it's wavelength are related by Eλ = X. the numerical value of X is?
[h = 6.63 x 10-34js, c = 3 x 108 ms-1]
回答
(D)
1.99 x 10-25
23
The bond that forms a semiconductor is?
回答
(A)
covalent
24
Silicon doped with aluminum and germanium doped with arsenic become?
回答
(A)
p- and n- types respectively
25
The figure above shows 4 forces 3N, 10N, 3√3N and 6N acting on a particle P. The resultant of he four forces is
回答
(C)
10N
26
From the diagram above, the bob of the pendulum has the fastest speed at
回答
(A)
X
27
In the diagram above, a rod 50 cm long of uniform cross-section is suspended horizontally on a fulcrum, F, by the action of two forces. What is the weight of the rod?
回答
(B)
80N
28
A boy drags a bag of rice along a smooth horizontal floor with a force of 2N applied at the angle of 60o to the floor. The work done after a distance of 3m is
回答
(A)
3 J
29
A blacksmith heated a metal whose cubic expansivity is 6.3 x 10\(^{-6}\)K\(^{-1}\). The area expansivity is
回答
(C)
4.2 x 10-6K-1
30
The ratio of the coefficient of linear expansion of two metals ∝1/∝2 is 3:4. If, when heated through the same temperature change, the ratio of the increase in length of the two metals, e1/e2 is 1:2, the ratio of the original lengths l1/l2 is
回答
(C)
2/3
31
The fundamental frequency of a plucked wire under a tension of 400N is 250Hz. When the frequency is changed to 500 Hz at constant length, the tension is
回答
(A)
1600N
32
Three cells each of e.m.f 1.5 V and internal resistance 2.5Ω are connected as shown in the diagram above. Find the net e.m.f and the internal resistance
回答
(B)
1,5V, 0.83Ω
33
In the diagram above , if the magnetic field points into the paper and the force on a current - carrying conductor points upwards, what is the direction of the current?
回答
(D)
Left
34
The instantaneous value of the induced e.m.f as a function of time is ε = εo sin ωt where εo is the peak value of the e.m.f. The instantaneous value of the e.m.f., one quarter of the period is
回答
(D)
εo
35
During the nuclear reaction described by
235
W →
235
X→
231
Y
92
93
91
the particles emitted are respectively
回答
(D)
β and α
36
from the diagram above, the inductive reactance and the resistance R are respectively
回答
(D)
10Ω and 50Ω
37
118.8cm2 surface of the copper cathode of a voltameter is to be coated with 10-6m thick copper of density 9 x 103kgm-3. How long will the process run with 10A constant current?
[3.3 x 10-7kgC-1]
回答
(A)
5.4 min
38
A particle of weight 120N is placed on a plane inclined at 300 to the horizontal. If the plane has an efficiency of 60% to the floor what is the force required to push the weight uniformly up the plane?
回答
(B)
100N
39
A string of length 4m is extended by 0.02m when a load of 0.4kg is suspended at its end. What will be the length of the string when the applied force is 15N?
回答
(B)
4.08m
40
Which of the following gas laws is equivalent to the work done?
回答
(A)
Boyle' law
41
The difference observed in solids, liquids and gases can be accounted for by
回答
(B)
The spaces and forces acting between the molecules
42
If two charged plates are maintained at a potential difference of 3 kv, the work done in taking a charge of 600µc across the field is
回答
(B)
1.8j
43
A conductor has a diameter of 1.00mm and length of 2.00m. If the resistance of the material is 0.1Ω, the resistivity is
回答
(D)
3.93 * 10-8 Ωm
44
A 40KW electric cable was used to transmit electricity through a resistor of resistance 2.00Ω at 800V. The power loss as internal energy is
回答
(D)
5.0 x 103W
45
The instrument that measures both ac and dc is called
