Infrared radiation is detected by

Heat given to a body which raises its temperature by $$1^{\circ }C$$ is

Which of the following is more close to a black body?

If mass-energy equivalence is taken into account, when water is cooled to form ice, the mass of water should

Cooking gas containers are kept in a lorry moving with uniform speed. The temperature of the gas molecules inside will

Even Carnot engine cannot give $$100\%$$ efficiency because we cannot

At what temperature is the $$r.m.s$$ velocity of a hydrogen molecule equal to that of an oxygen molecule at $$47^{\circ }C?$$

1 mole of a gas with $$\gamma =7/5$$ is mixed with $$1$$ mole of a gas with $$\gamma =5/3,$$ then the value of $$\gamma$$ for the resulting mixture is

Two spheres of the same material have radii $$1$$ $$m$$ and $$4$$ $$m$$ and temperatures $$4000$$ $$K$$ and $$2000$$ $$K$$ respectively. The ratio of the energy radiated per second by the first sphere to that by the second is

On moving a charge of $$20$$ coulomb by $$2$$ $$cm,$$ $$2$$ $$J$$ of work is done, then the potential differences between the points is

A charged particle $$q$$ is placed at the centre $$O$$ of cube of length $$L(ABCDEFGH).$$ Another same charge $$q$$ is placed at a distance $$L$$ from $$O$$. Then the electric flux through $$ABCD$$ is

If a charge $$q$$ is placed at the center of the line joining two equal charges $$Q$$ such that the system is in equilibrium then the value of $$q$$ is

From a building two balls A and B are thrown such that A is thrown upwards and B downwards ( both vertically with the same speed ). If vA and vB are their respective velocities on reaching the ground, then

Speeds of two identical cars are $$u$$ and $$4$$$$u$$ at the specific instant. The ratio of the respective distances in which the two cars are stopped from that instant is :

Sodium and copper have work functions $$2.3$$ $$eV$$ and $$4.5$$ $$eV$$ respectively. Then the ratio of the wavelengths is nearest to

Formation of covalent bonds in compounds exhibits

The kinetic energy needed to project a body of mass $$m$$ from the earth surface (radius $$R$$) to infinity is

If suddenly the gravitational force of attraction between Earth and a satellite revolving around it becomes zero, then the satellite will

The escape velocity of a body depends upon mass as

Energy required to move a body of mass $$m$$ from an orbit of radius $$2R$$ to $$3R$$ is