The vacuum and silvered wall surfaces of a vacuum flask walls are respectively
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(B)
prevent conduction and convection and minimize radiation
2
The magnitude of the acceleration of a moving object is equal to the
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(B)
gradient of a velocity-time graph
3
In which of the following states is MAXIMUM pressure exerted on a person
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(B)
Standing on one foot
4
What are cathode rays?
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(A)
Stream of electrons
5
The capacitance of a parallel plate capacitor
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(D)
is greater with dielectric between the plates than without dielectric.
6
The diagram above illustrates the motion of a cyclist from P to R. The distance travelled is determined by the
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(B)
area under PQR
7
A ray of light travels from a less dense medium to a denser medium. How are the speed and frequency of the light affected? The speed
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(D)
decreases and the frequency remains the same
8
The function of a fuse in an electric circuit is to
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(A)
break the circuit when the current exceeds a certain value
9
A body moves with uniform velocity when the resultant force on it is
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(C)
equal to zero
10
The law of conservation of momentum is stated for closed and isolated system. What are the two conditions for a system to be closed and isolated?
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(A)
No external force acts on the system and there is no change in mass of the system.
11
A stone of mass 200 g attached to a string is made to revolve in a horizontal circle of radius 1.5 m at a steady speed of 5 m/s. Calculate the tension in the string at the bottom of the circle.
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(A)
5.3 N
12
To convert a milli-ammeter to an ammeter, a resistor of low value is necessary to connect a resistor of
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(C)
low value in parallel with it
13
An object is placed 1.5 m from a plane mirror. How far is the image from the object?
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(A)
3.0 m
14
Chromatic aberration in lenses can be corrected by using a combination of
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(A)
diverging and converging lenses.
15
A cube of water with side 10.0 cm floats vertically in water with 4.5 cm its length submerged. Calculate the density of the wood.
[Density of water = 1 g/cm\(^3\); D = 0.090 g/cm\(^3\)]
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(B)
0.450 g/cm\(^3\)
16
A temperature of 60º C is equivalent to
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(B)
140ºF
17
All of the following uses are practical applications of x-ray except
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(B)
determining the depth of a mine
18
Two isolated charged spheres each of magnitude + 1.0 x 10\(^{-6}\) C are seperated by a distance of 2.0 x 10\(^{-1}\) m. Calculate the magnitude of the electrostatic force between them [K = \(\frac{1}{4\pi \epsilon_o}\) = 9 x 10\(^9\)Nm\(^2\)C\(^{-2}\)]
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(A)
2.25 x 10\(^{-1}\)N
19
In the circuit diagram above, which lamp causes the other to go off?
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(D)
S
20
A particle of mass 3.6 x 10\(^{-6}\)kg revolving around the earth has a radial acceleration of 4.3 x 10\(^7\)ms\(^{-2}\). Calculate the centripetal force of the particle.
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(A)
1.55 x 10\(^2\)N
21
For a convex lens to form a real image, the distance between the object and the screen will be:
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(C)
twice the focal length of the lens
22
A constant voltage source supplies a sinusoidal alternating e.m.f. The voltage marked against the components are their peak values. Determine the peak value of the applied e.m.f
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(C)
5V
23
A 2 μF capacitor is connected directly across a 150 V\(_{rms}\), 60 Hz A.C source. Calculate the r m s value of the current.
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(A)
0.113 A
24
A body of mass, m is projected vertically upward with a velocity, y. At what position will the potential energy be maximum?
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(C)
\(\frac{y^2}{2g}\)
25
Light of energy 1.12 x 10\(^{-18}\) J is incident on a metal of ejected electrons with maximum energy of 8.0 x 10\(^{-19}\)J. Calculate the threshold frequency of the metal. [h = 6.626 x 10\(^{-34}\)Js]
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(A)
4.8 x 10\(^{14}\)Hz
26
An object 2.0 cm high is placed at the radius of curvature of a concave mirror such that it is perpendicular to the principal axis of the mirror. Determine the height of the image.
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(D)
2.0 cm
27
The diagram above illustrates two boxes P and Q of masses 27.3 kg and 6.2 kg respectively on a smooth horizontal surface. If a force F of 150 N is applied to the combined forces, calculate the acceleration.
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(A)
4.5 ms\(^{-2}\)
28
A boy of mass 40 kg jumps off a stationary skateboard and moves horizontally with a speed of 1.5 m/s while the skateboard moves in the opposite direction with a speed of 20 m/s. Calculate the mass of the skateboard.
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(C)
3 kg
29
The depolarizing agent in a Leclanché cell is
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(B)
manganese (IV) oxide.
30
Which of the following terms has different dimension from the others?
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(D)
Torque
31
A capacitor described as a mica capacitor has
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(C)
a dielectric made of mica
32
In which of the following devices is the thermal expansion considered a disadvantage?
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(D)
Balance wheel of a watch
33
The inside portion of a hollow metal sphere of diameter 20 cm is polished. The portion will therefore form a
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(D)
Convex mirror of focal length 5cm
34
Which of the following statements about a projectile is not correct?
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(C)
The range of a projectile is independent of the acceleration due to gravity.
35
Atmospheric pressure decreases with an increase in altitude because:
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(D)
Interaction among air molecules decreases due to less quantity of air.
36
The main difference between X-rays and gamma rays is in their
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(D)
mode of production.
37
The phenomenon used for explaining the formation of a rainbow in the sky is
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(D)
dispersion.
38
Which of the following modes is the most economical method of transmitting electrical power over a long distance?
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(A)
Alternating current at high voltage and low current.
39
The correct sequence of ionization power of alpha particle, gamma ray, and beta particle respectively is
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(D)
high, low, medium.
40
Four pieces of constantan wire, marked E, F, G, and H, each of length 1.0m, are at the temperature. Their respective diameters are 1 mm, 2 mm, 6 mm, and 10 mm. Which wire has the highest resistance?
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(A)
E
41
The maximum displacement of particles from equilibrium position in a wave motion is known as
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(B)
amplitude.
42
A non-conducting vessel contains a liquid of mass 70 g at 25º C. Another 70.0g of the same liquid at 35ºC is quickly poured into the vessel. Determine the final temperature of the mixture
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(C)
30ºC
43
A galvanometer of full-scale deflection 10 mA has a resistance of 5\(\Omega\). Calculate the shunt needed to convert it to measure currents of 2 A.
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(A)
0.025\(\Omega\)
44
In storing magnets, the keeper is used to
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(B)
reduce self demagnetization
45
Which of the following factors does not affect the speed of sound?
