ln which of the processes, does the internal energy of the system remain constant?
The focal length of a plano convex lens is 'f' and its refractive index is 1.5. It is kept over a plane glass plate with its curved surface touching the glass plate. The gap between the lens and the glass plate is filled by a liquid. As a result, the effective focal length of the combination becomes 2f. Then the refractive index of the liquid is ______.
A current is said to exist whenever _____.
If we drop a ball in horizontal direction than its motion will no longer be straight downward but will be at some?
An astronaut on a strange planet finds that acceleration due to gravity is twice as that on the surface of Earth. Which of the following could explain this?
Consider the following statements :
(1) A light and a heavy body, having equal momenta, have equal kinetic energies.
(2) The total energy of a body in motion is equal to the work it can do in being brought to rest.
(3) A body cannot have momentum when its energy is zero.
Which of these statement(s) is/are correct ?
Atom is the smallest part of matter which takes part in chemical reactions.
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 weight of the body is given by?
If alpha, beta and gamma rays carry same momentum, which has the longest wavelength?
With what velocity should an observer approach a stationary sound source so that the apparent frequency of sound should appear double the actual frequency? (v is velocity of sound).
Which instrument is used to record physical happenings at a distant place ?
The horizontal distance from the origin (x=O, y=O) to the point where the projectile returns (x = R, y=O) is called?
Which one of the following statements is not true for a person suffering from hypermetropia?
A time dependent force F = 6t acts on a particle of mass 1 kg. If the particle starts from rest, the work done by the force during the first 1 sec. will be :
Of the four locations mentioned below the highest inside temperature will be attained in the pressure cooker operated with the pressure valve open
The incident ray, reflected ray and normal to the reflecting surface at the incident point all never lie in same plane.
A radio active substance contains 10,000 nuclei and its half life period is 20 days. The number of nuclei present at the end of 10 days is
A circular coil carrying a certain current produces a magnetic field Bo at its centre. The coil is now rewound so as to have 3 turns and the same current is passed through it. The new magnetic field at the centre is
Maximum diffraction takes place in a given slit for
If the acceleration due to gravity of a planet is half the acceleration due to gravity of earth’s surface and radius of planet is half the radius of the earth, the mass of planet in terms of mass of earth is
Inside an aeroplane, flying at a high altitude,
Suppose a rocketship is receding from the earth at a speed of 2/10 th the velocity of light. A light in the rocketship appears blue to the passengers on the ship. What colour would it appear to an observer on the earth?
A liquid drop tends to assume a spherical shape because of
A man inside an artificial satellite feels weightlessness because the force of attraction due to earth is
An external pressure P is applied on a cube at 0°C so that it is equally compressed from all sides. K is the bulk modulus of the material of the cube and is its coefficient of linear expansion. Suppose we want to bring the cube to its original size by heating. The temperature should be raised by :
Pick out the scalar quantity
The temperature of a gas contained in a closed vessel of constant volume increases by 1°C when the pressure of the gas is increased by 1%. The initial temperature of the gas is ______.