In a coil of resistance 100 , a current is induced by changing the magnetic flux through it as shown in the figure. The magnitude of change in flux through the coil is : 10 Current (amp.) sec Time 0.5
What is the maximum value of deforming force upto which a material shows elastic property and above which the material loses it ?
When body is raised to a height equal to radius of earth, the P.E. change is
If the wire of uniform area of cross-section is cut into two equal parts, the resistivity of each parts will be?
Newton is used to measure
The motion of falling bodies towards earth is due to the?
Consider the following statements and select the correct code.
Assertion (A): The temperature of a metal wire rises when an electric current is passed through it.
Reason (R): Collision of metal atoms with each other releases heat energy.
What is refractive index ?
In parallel connection the current flows through each resistor is?
A convex and a concave lens seperated by distance d are then put in contact. The focal length of the combination
A simple pendulum is suspended from the ceiling of a lift. When the lift is at rest its time period is T. With what acceleration should the lift be accelerated upwards in order to reduce its period to T /2? (g is acceleration due to gravity).
The minimum height of a plane mirror to see the full size image of a person is equal to
Two beams of red and violet colours are made to pass separately through a prism of A = 60°. In the minimum deviation position, the angle of refraction inside the prism will be
The force on the object placed near the surface is given by the mass “m” of the object multiplied by the acceleration due to gravity, which is equal to its?
A body floats in water with 40% of its volume outside water. When the same body floats in an oil, 60% of its volume remains outside oil. The relative density of oil is
Heavy water is used as a moderator in a nuclear reactor. The function of the moderator is
Which instrument is used in submarine to see the objects above sea level ?
Two resistance r1 and r2 (r1 < r2 ) are connected in parallel. Their equivalent resistance R is
A body of mass m = 10–2 kg is moving in a medium and experiences a frictional force F = –kv2. Its intial speed is v0 = 10 ms–1. If, after 10 s, its energy is 1 2 mv0 , the value of k will be:-
Which are the primary Colours ?
The ratio of minimum wavelengths of Lyman and Balmer series will be
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
The cloudy nights are warmer than clear nights because
When resistors are connected in series, their equivalent resistance is given by?
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
Consider the following statement:
The principle of total internal reflection is
applicable to explain the
1. Formation of mirage in desert.
2. Formation of image in microscope.
3. Colour of evening sky.
4. Operation of optical fibres.
Which of the statement given above are correct?