Alternating Current — Physics STD 12 Science — Question

An object 2.5 cm high is placed at a distance of 10 cm   from a concave mirror of radius of curvature 30 cm  The size of the image is

(a) 9.2 cm

(b) 10.5 cm

(c) 5.6 cm

(d) 7.5 cm

Nuclear fusion occur in.

The de-Broglie wavelength of an electron in the first Bohr orbit is

(a) Equal to one fourth the circumference of the first orbit

(b) Equal to half the circumference of the first orbit

(c) Equal to twice the circumference of the first orbit

(d) Equal to the circumference of the first orbit

Action and reaction:

1. Act on two different objects.
2. Have equal magnitude.
3. Have opposite directions.
4. Have resultant zero.

In order to pass 10% of main current through a moving coil galvanometer of 99 ohm, the resistance of the required shunt is

(a) 9.9 Ω

(b) 10 Ω

(c) 11 Ω

(d) 9 Ω

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

(a) Greater than at Q

(b) Same as at Q

(c) Less than at Q

(d) Greater or less than at Q depending upon the strength of the current

___________ radiations are used in LASIK eye surgery.

The relation between Faraday constant (F), chemical equivalent (E) and electrochemical equivalent (Z) is

(a) F = EZ

(b)

(c)

(d)

In the experiment of potentiometer, at balance, there is no current in the

(a) Main circuit

(b) Galvanometer circuit

(c) Potentiometer circuit

(d) Both main and galvanometer circuits