Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

In Fresnel’s biprism experiment, on increasing the prism angle, fringe width will

(a) Increase	(b) Decrease
(c) Remain unchanged	(d)  Depend on the position of object

A smaller sphere has potential 50V and a larger sphere has potential 100V. How should they be placed so that if they are connected with the help of a wire, the charge will flow from the smaller sphere to the larger sphere? Both the spheres are conducting and hollow.

Each plate of a parallel plate capacitor has a charge q on it. The capacitor is now connected to a batter. Now:

1. The facing surfaces of the capacitor have equal and opposite charges.
2. The two plates of the capacitor have equal and opposite charges.
3. The battery supplies equal and opposite charges to the two plates.
4. The outer surfaces of the plates have equal charges.

When hydrogen atom is in its first excited level, it’s radius is:

The specific charge of an electron is

(a) 1.6	(b) 4.8
(c) 1.76	(d) 1.76

A plane mirror produces a magnification of

(a) -1

(b) +1

(c) Zero

(d) Between 0 and +∞

A photo cell is a device which:

Assertion  :   In Hertz experiment, the electric vector of radiation produced by the source gap is parallel to the gap.

Reason      : Production of sparks between the detector gap is maximum when it is placed perpendicular to the source gap.

(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.

At neutral temperature, the thermoelectric power   has the value

(a) Zero	(b) Maximum but negative
(c) Maximum but positive	(d) Minimum but positive

A magnet NS is suspended from a spring and while it oscillates, the magnet moves in and out of the coil C. The coil is connected to a galvanometer G. Then as the magnet oscillates,

(a) G shows deflection to the left and right with constant amplitude

(b) G shows deflection on one side

(c) G shows no deflection.

(d) G shows deflection to the left and right but the amplitude steadily decreases.