Magnetism And Matter — Physics STD 12 Science — Question

In an adjoining figure are shown three capacitors   and   joined to a battery. The correct condition will be (Symbols have their usual meanings)

(a)  and	(b)  and
(c)  and	(d)   and

In a purely inductive circuit, the current:

Resolving power of a telescope increases with:

Assertion :   Only a change in magnetic flux will maintain an induced current the coil.

Reason     : The presence of large magnetic flux through a coil maintains a current in the coil if the circuit is continuous.

(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.

A convex lens makes a real image 4 cm long on a screen. When the lens is shifted to a new position without disturbing the object, we again get a real image on the screen which is 16 cm tall. The length of the object must be

(a) 1/4 cm

(b) 8 cm

(c) 12 cm

(d) 20 cm

If an electron and a proton have the same de-Broglie wavelength, the K.E of electrons is:

Antinodal curves correspond to _____ interference.

On increasing the distance between the light source and the photoelectric cell, the value of stopping potential changes :

Assertion :  No interference pattern is detected when two coherent sources are infinitely close to each other.

Reason     : The fringe width is inversely proportional to the distance between the two slits.

(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.