Electromagnetic Induction — Physics STD 12 Science — Question

The work function of a metal is 1.6  J. When the metal surface is illuminated by the light of wavelength  6400 Å, then the maximum kinetic energy of emitted photo-electrons will be (Planck's constant h = 6.4 )

(a) 14

(b) 2.8

(c) 1.4

(d) 1.4

A metal surface of work function 1.07 eV is irradiated with light of wavelength 332 nm. The retarding potential required to stop the escape of photo-electrons is

(a) 4.81 eV

(b) 3.74 eV

(c) 2.66 eV

(d) 1.07 eV

The plates of a parallel plate condenser are pulled apart with a velocity v. If at any instant their mutual distance of separation is d, then the magnitude of the time of rate of change of capacity depends on d as follows

(a)

(b)

(c)

(d) d

The primary origin (s) of magnetism lies in:

In the figure, an air lens of radii of curvature 10 cm (= 10 cm) is cut in a cylinder of glass (μ = 1.5). The focal length and the nature of the lens is

(a) 15 cm, concave	(b) 15 cm, convex
(c) ∞, neither concave nor convex	(d) 0, concave

Two similar bar magnets P and Q, each of magnetic moment M, are taken, If P is cut along its axial line and Q is cut along its equatorial line, all the four pieces obtained have

(a) Equal pole strength	(b) Magnetic moment
(c) Magnetic moment	(d) Magnetic moment M

In Young's double slit experiment, the distance between the slits is 1 mm and that between slit and screen is 1 meter and 10th fringe is 5 mm away from the central bright fringe, then wavelength of light used will be

(a) 5000 Å

(b) 6000 Å

(c) 7000 Å

(d) 8000 Å

The velocity of light in a medium is half its velocity in air.  If ray of light emerges from such a medium into air, the angle of incidence, at which it will be totally internally reflected,   is

(a) 15o

(b) 30 o

(c) 45 o

(d) 60 o

A dip circle is at right angle to the magnetic meridian. What will be the apparent dip

(a) 0°

(b) 30°

(c) 60°

(d) 90°