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

Cylindrical lenses are used to correct the eye defect called :

The photoelectric effect can be understood on the basis of:

L, C and R represent the physical quantities inductance, capacitance and resistance respectively. Which of the following combinations have dimensions of frequency?

The current from the battery in circuit diagram shown is

(a) 1 A

(b) 2 A

(c) 1.5 A

(d) 3 A

A semiconductor is a material with a small but non-zero band gap that behaves as an insulator at absolute zero but allows thermal excitation of electrons into its ____________ at temperatures that are below its melting point.

The line that draws power supply to your house from street has:

Assertion :   Penetrating power of X-rays increases with the increasing the wavelength.

Reason    : The penetrating power of X-rays increases with the frequency of X-rays.

(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 assertion is false but reason is true.

The north pole of a long horizontal bar magnet is being brought closer to a vertical conducting plane along the perpendicular direction. The direction of the induced current in the conducting plane will be

(a) Horizontal

(b) Vertical

(c) Clockwise

(d) Anticlockwise

I a.m.u. is equivalent to the energy of :

(1) The product of a volt and a coulomb is a joule.

(2)  The product of a volt and an ampere is a joule/second.

(3)  The product of volt and watt is horse power.

(4)  Watt-hour can be measured in terms of electron volt.

State if

(a) All four are correct	(b) (1), (2) and (4) are correct
(c) (1) and (3) are correct	(d) (3) and (4) are correct