Electronics — JEE physics STD 12 Science — Question

Assertion : Cars and aeroplanes are streamlined.
Reason : This is done to reduce the backward drag due to atmosphere.

Assertion : Dispersion of light occurs because velocity of light in a material depends upon its colour.
Reason : The dispersive power depends only upon the material of the prism, not upon the refracting angle of the prism.

Assertion : Two bodies at different temperatures, if brought in thermal contact do not necessary settle to the mean temperature.
Reason : The two bodies may have different thermal capacities.

Assertion : Electric field outside the conducting wire which carries a constant current is zero.
Reason : Net charge on conducting wire is zero.

Assertion : A bullet is fired from a rifle. If the rifle recoils freely, the kinetic energy of rifle is more than that of the bullet.
Reason : In the case of rifle bullet system the law of conservation of momentum violates.

Assertion : When a body is subjected to a uniform acceleration, it always move in a straight line.
Reason : Straight line motion is the natural tendency of the body.

Assertion : Ocean waves hitting a beach are always found to be nearly normal to the shore.
Reason : Ocean waves are longitudinal waves.

Assertion : Air quickly leaking out of a balloon becomes coolers
Reason : The leaking air undergoes adiabatic expansion.

Assertion : For the sensitivity of a camera, its aperture should be reduced.
Reason : Smaller the aperture, image focussing is also sharp.

Assertion : The properties of paramagnetic and ferromagnetic substance are not effected by heating.
Reason : As temperature rises, the alignment of molecular magnets gradually decreases.