A Carnot's engine operates with source at 127°C and sinks at 27°C. If the source supplies 40 kJ of heat energy, the work done by the engine is
92U235 undergoes successive disintegrations with the end product of 82Pb203. The Number of a and b particles emitted are
Newton is used to measure
The escape velocity from the earth’s surface is 11 km/sec. A certain planet has a radius twice that of the earth but its mean density is the same as that of the earth. The value of the escape velocity from this planet would be
Rainbow is produced when sunlight fall on drops of rain. Which of the following physical phenomena are responsible for this?
(i) Diffusion
(ii) Refraction
(iii) Internal reflection
Which of the following is an electromagnetic wave ?
In Young's double slit experiment, a third slit is made in between the double slits. Then
A closed organ pipe and an open organ pipe of same length produce 2 beats/second while vibrating in their fundamental modes. The length of the open organ pipe is halved and that of closed pipe is doubled. Then, the number of beats produced per second while vibrating in the fundamental mode is ______.
Pa(Pascal) is the unit for
Large astronomical telescopes always use as objective
A fan produces a feeling of comfort during hot weather because
What are audible sound waves ?
A ball is dropped from a satellite revolving around the earth at a height of 120 km. The ball will
If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant. Which law states this ?
The centripetal force acting on a satellite orbiting round the earth and the gravitational force of earth acting on the satellite both equal F. The net force on the satellite is
The S.l unit of electromotive force is?
A 20 cm length of a certain solution causes right handed rotation of 38°. A 30 cm length of another solution causes left handed rotation of 24°. The optical rotation caused by 30 cm length of a mixture of the above solutions in the volume ratio 1 : 2 is
A man is standing on a boat in still water. If he walks towards the shore, the boat will
How many times more intense is a 60 dB sound than a 30 dB sound?
A current flows in a conductor from east to west. The direction of the magnetic Held at a point above the conductor is _______.
Which instrument is used to measure pressure of gases ?
If the radius of the earth were to shrink by one percent, its mass remaining the same, the acceleration due to gravity on the earth’s surface would
A material has Poisson's ratio 0.50. If a uniform rod of it suffers a longitudinal strain of 2 × 10–3, then the percentage change in volume is
The SI unit of resistance is?
When a p.d is applied across a conductor, the electrons experience a force in?
It is a straight line with –ve slope.
A radioactive nucleus A with a half life T, decays into a nucleus B. At t = 0, there is no nucleus B. At sometime t, the ratio of the number of B to that of A is 0.3. Then, t is given by :
Consider the following statements:
1. The gravitational force exerted by the sun on the moon is greater than the gravitational force exerted by the earth on the moon.
2. A heavy body falls at a faster rate than a light body in vacuum.
Which of the following statements given above is/are correct ?
A hydrogen-inflated polythene balloon is released from the surface of the earth. As the balloon rises to an altitude up in the atmosphere, it will