Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

In a working nuclear reactor, Cadmium rods, (control rods) are used to

(a) Speed up neutrons	(b) Slow down neutrons
(c) Absorb some neutrons	(d) Absorb all neutrons

Assertion  :   The specific charge of positive rays is not constant.

Reason      : The mass of ions varies with speed.

(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.

Conditions of diffraction is

(a)

(b)

(c)

(d) None of these

Which of the following is used in optical fibers?

In the Boolean algebra, the following one is wrong:

A vertical wire carries a current in upward direction. An electron beam sent horizontally towards the wire will be deflected:

The leakage current across a pn junction is due to _________:

Light of wavelength  strikes a photo-sensitive surface and electrons are ejected with kinetic energy E. If  the kinetic energy is to be increased to 2E, the wavelength must be changed to   where

(a)

(b)

(c)  <

(d)

The condensers of capacity  and  are connected in parallel, then the equivalent capacitance is

(a)

(b)

(c)

(d)