Electronics — JEE physics STD 12 Science — Question

Assertion : A pulsor is a source of radio waves which change in terms of intensity at regular interval of time
Reason : A pulsor is a rotating neutron star

Assertion : To empty an oil tank, two holes are made.
Reason : Oil will come out two holes so it will emptied faster.

Assertion : Bending a wire does not effect electrical resistance.
Reason : Resistance of wire is proportional to resistivity of material.

Assertion : The shape of a liquid drop is spherical.
Reason : The pressure inside the drop is greater than that of outside.

Assertion : Spherical aberration occur in lenses of larger aperture.
Reason : The two rays, paraxial and marginal rays focus at different points.

Assertion : In a movie, ordinarily 24 frames are projected per second from one end to the other of the complete film.
Reason : The image formed on retina of eye is sustained upto 1/10 second after the removal of stimulus.

Assertion : For a floating body to be in stable equilibrium, its centre of buoyancy must be located above the centre of gravity.
Reason : The torque produced by the weight of the body and the upthrust will restore body back to its normal position, after the body is disturbed.

Assertion : A body may be accelerated even when it is moving uniformly.
Reason : When direction of motion of the body is changing then body may have acceleration.

Assertion : The focal length of lens does not change when red light is replaced by blue light.
Reason : The focal length of lens does not depends on colour of light used.