Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

Assertion  :  If a charged particle is moving on a circular path in a perpendicular magnetic field, the momentum of the particle is not changing,.
Reason     : Velocity of the particle in not changing in the magnetic field.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

When the particle and its anti-particle unite, the result is:

For which of the following colour, the magnifying power of a microscope will be maximum(a) White colour (b)  Red colour (c) Violet colour (d)  Yellow colour 

A thin glass (refractive index 1.5) lens has optical power of -5D in air. It's optical power in a liquid medium with refractive index 1.6 will be(a) 25 D   (b) – 25 D(c) 1 D     (d) None of these

Work done to bring a unit positive charge from infinity to a point in an electric field is known as _______?

The unit for molar susceptibility is

A steady electric current is flowing through a cylindrical conductor.

1. The electric field at the axis of the conductor is zero.
2. The magnetic field at the axis of the conductor is zero.
3. The electric field in the vicinity of the conductor is zero.
4. The magnetic field in the vicinity of the conductor is zero.

Work done by an external agent in separating the parallel plate capacitor is

Among the two interfering monochromatic sources A and B; A is ahead of B in phase by 66°. If the observation be taken from point P, such that PB – PA = l/4. Then the phase difference between the waves from A and B reaching P is (a) 156°(b) 140°(c) 136°(d) 126°