Wave Optics — Physics STD 12 Science — Question

Which material sheet should be placed between the plates of a parallel plate condenser in order to increase its capacitance ?

A circular coil and a bar magnet moves with the same velocity. Then

A heavy nucleus at rest breaks into two fragments which fly off with velocities in the ratio 8 : 1. The ratio of radii of the fragments is (a) 1 : 2(b) 1 : 4(c) 4 : 1(d) 2 : 1

Assertion  :   A spark occur between the poles of a switch when the switch is opened.
Reason      : Current flowing in the conductor produces 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.

Cathode rays enter into a uniform magnetic field perpendicular to the direction of the field. In the magnetic field their path will be(a) Straight line(b) Circle(c) Parabolic(d) Ellipse

Voltameter measures :

Magnetic dipole moment of a rectangular loop is:

Critical angle is that angle of incidence in the denser medium for which the angle of refraction in rarer medium is(a) 0° (b) 57°(c) 90°(d) 180°