Alternating Current — Physics STD 12 Science — Question

A wire loop is rotated in a uniform magnetic field about an axis perpendicular to the field. The direction of the current induced in the loop reverse once each.

A vertical straight conductor carries a current vertically upwards. A point P lies to the east of it at a small distance and another point Q lies to the west at the same distance the magnetic field at P is:

Assuming photoemission to take place, the factor by which the maximum velocity of the emitted photoelectrons changes when the wavelength of the incident radiation is increased four times, is

The following truth table corresponds to the logic gate (a) NAND    (b) OR(c) AND(d) XOR

If the refractive indices of crown glass for red, yellow and violet colours are 1.5140, 1.5170 and 1.5318 respectively and for flint glass these are 1.6434, 1.6499 and 1.6852 respectively, then the dispersive powers for crown and flint glass are respectively(a) 0.034 and 0.064(b) 0.064 and 0.034(c) 1.00 and 0.064(d) 0.034 and 1.0

Let V and E denote the gravitational potential and gravitational field at a point. It is possible to have:

1. V = 0 and E = 0
2. V = 0 and E ≠ 0
3. V ≠ 0 and E = 0
4. V ≠ 0 and E ≠ 0

In a purely inductive circuit, the current: