Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

Given below are symbols for some logic gates

The XOR gate and NOR gate respectively are

(a) 1 and 2

(b) 2 and 3

(c) 3 and 4

(d) 1 and 4

Gauss is unit of which quantity

(a) H

(b) B

(c) ∅

(d) I

The impurity atoms with which pure silicon may be doped to make it a p-type semiconductor are those of:

The self inductance L of a solenoid of length l and area of crosssection A, with a fixed number of turns N increases as:

The current in the given circuit is

(a) 8.31 A

(b) 6.82 A

(c) 4.92 A

(d) 2 A

A metal wire is subjected to a constant potential difference. When the temperature of the metal wire increases, the drift velocity of the electron in it:

A white screen illuminated by green and red light appears to be

(a) Green

(b) Red

(c) Yellow

(d) White

The drift current in a p-n junction is from the:

Photo cell is  a device to

(a) Store photons

(b) Measure light intensity

(c) Convert photon energy into mechanical energy

(d) Store electrical energy for replacing storage batteries

A concave mirror is used to focus the image of a flower on a nearby well 120 cm from the flower. If a lateral magnification of 16  is desired, the distance of the flower from the mirror should be

(a) 8 cm

(b) 12 cm

(c) 80 cm

(d) 120 cm