Which of the following is not a consequence of a force field?
Απάντηση
(B)
surface tension
3
A boy pulls a nail from the wall with a string tied to the nail. The string is inclined at an angle of 60o to the wall. If the tension in the string is 4N, what is the effective force used in pulling the nail?
Απάντηση
(A)
2√3 N
4
Which of the following is used to determine the relative density of the acid in a car battery?
Απάντηση
(D)
Hydrometer
5
A block of material of volume 20cm-3 and density 2.5gcm-3 is suspended from a spring balance with half the volume immersed in water. What is the reading of the spring balance? (Density of water = 1.0gcm-3).
Απάντηση
(D)
40g
6
A piece of cork floating on water is acted upon by the forces of...
Απάντηση
(B)
weight and upthrust
7
A stone tied to a string is made to revolve in a horizontal circle of radius 4m with an angular speed of 2 rad per sec. With what tangential velocity will the stone move off the circle if the string is cut?
Απάντηση
(B)
8.0 ms-1
8
The motion of the prongs of the sounding tuning fork is
Απάντηση
(D)
vibratory
9
Which of the following is a derived unit?
Απάντηση
(B)
Coulomb
10
An engine raises 1000kg of water through a height of 60m in 20s. What is the power of the engine? (Take g = 10ms-2>).
Απάντηση
(B)
30,000 W
11
A thermometer has its stem marked in millimeter instead of degree Celsius. The lower fixed point is 30mm and the upper is 180mm. Calculate the temperature in degree celsius when the thermometer reads 45mm.
Απάντηση
(E)
10.0oC
12
Which of the following surfaces will radiate heat energy best?
Απάντηση
(C)
Black
13
Which of the followiempeng statements is/are not correct?
Απάντηση
(E)
The boiling point of a liquid is not affected by impurities
14
Water in an open container boils at a lower temperature when heated at the top of a mountain than at sea-level because at the top of a mountain the
Απάντηση
(D)
pressure is lower than that at sea-level
15
Which of the following substance is not a good conductor of electricity?
Απάντηση
(B)
Glass
16
Calculate the heat energy required to vapourize 50g of water initially at 80oC if the specific heat capacity of water is 4.2Jg-1K (specific latent heat of vapourization of water is 2260Jg-1).
Απάντηση
(C)
117200J
17
A block of ice at its melting point is left on a table in the atmosphere and observed to melt gradually. Which of the following statements is true about the melting process?
Απάντηση
(E)
the ice block absorbs heat from the atmosphere and its temperature remains constant as it melts
18
All the heat generated by a current of 2A passing through a resistor of 6Ω for 25s is used to evaporate 5 g of a liquid at its boiling point. What is the specific latent heat of the liquid?
Απάντηση
(B)
120 Jg-1
19
Which of the following instruments can be used to compare the relative magnitudes of charges on two given bodies?
Απάντηση
(D)
Gold leaf electroscope
20
A short chain is usual attached to the back of a petrol tanker trailing behind it to ensure that the
Απάντηση
(C)
charges generated by friction in the tanker can be conducted to the earth
21
A ray of light is incidence on a plane mirror at an angle of 35o. What is the angle by the reflected ray with the surface of the mirror?
Απάντηση
(D)
55o
22
The image in a pine-hole camera is always
Απάντηση
(D)
inverted
23
The refractive index of a given transparent medium is 1.4. Which of the following is the minimum internal angle for total internal reflection to take place in the medium?
Απάντηση
(D)
46o
24
The distance between a node and an anti-node for a transverse wave is equal to
Απάντηση
(D)
one-quater of the wavelength
25
Which of the following is a stringed instrument?
Απάντηση
(C)
piano
26
A sound pulse sent vertically downwards into the earth is reflected from two different layers of the earth such that echoes are heard 1.2s and 1.4s. Assuming speed of the pulse is 2000ms-1, calculate the distance between the layers.
Απάντηση
(A)
200 m
27
In a wave the maximum displacement of particles from their equilibrium positions is called.
Απάντηση
(B)
amplitude
28
A string is stretched between two points 50cm apart. It is then plucked at its center and the velocity of the wave produced is 300m/s. Calculate the number of vibrations made by the string in 1s.
Απάντηση
(D)
300
29
Which of the following is not a property of longitudinal waves?
Απάντηση
(D)
polarization
30
What is the gravitational potential due to a molecule of mass, m and at a distance, r from it? (G = gravitational constant).
