Physics Test 27...

The magnetic field and number of turns of the coil of an electric generator is doubled then the magnetic flux of the coil will:

AB and CD are smooth parallel rails, separated by a distance l, and inclined to the horizontal at an angle q. A uniform magnetic field of magnitude B, directed vertically upwards, exists in the region. EF is a conductor of mass m, carrying a current i. For EF to be in equilibrium,

Two different arrangements in which two square wire frames of same resistance are placed in a uniform constantly decreasing magnetic field B.

The direction of induced current in the case II is

The power factor of an RL circuit  If the frequency of a.c. is doubled, what will be the power factor?

What is the average power/cycle in a capacitor?

Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): The mirror formula 1/v + 1/u = 1/f is valid for mirrors of small aperture.

Reason (R): Laws of reflection of light is valid for only plane surface and not for large spherical surface.

Assertion (A): If the objective lens and the eyepiece lens of a microscope are interchanged, it works as a telescope.

Reason (R): Objective lens of telescope require large focal length and eyepiece lens require small focal length.

Which of the following statement is correct regarding AC generators?

In the series LCR circuit, the power dissipation is through:

In the given figure a metallic plate A is allowed to swing like a simple pendulum between the magnetic poles and it comes to rest after time t. If a slot is cut in the plate A and then it is allowed to swing with the same initial velocity as before then the time taken by it to come to rest will be: