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

Figure represents a glass plate placed vertically on a horizontal table with a beam of unpolarised light falling on its surface at the polarising angle of 57^o with the normal. The electric vector in the reflected light on screen S will vibrate with respect to the plane of incidence in a

(a) Vertical plane

(b) Horizontal plane

(c) Plane making an angle of 45o with the vertical

(d) Plane making an angle of 57o with the horizontal

When a hole is produced in P-type semiconductor, there is:

The equivalent resistance of the following infinite network of resistances is

(a) Less than 4 Ω	(b) 4 Ω
(c) More than 4 Ω  but less than 12 Ω	(d) 12 Ω

In vacuum an electron of energy 10 keV hits tungsten target, then emitted radiation will be       

(a) Cathode rays

(b) X-rays

(c) Infrared rays

(d) Visible spectrum

A radioactive sample of U²³⁸ decay to Pb through a process for which half life is 4.5 × 10⁹ years. The ratio of number of nuclei of Pb to U²³⁸ after a time  of 1.5 × 10⁹ years (given 2^1/3 = 1.26)

(a) 0.12

(b) 0.26

(c) 1.2

(d) 0.37

The inherent property of all materials is:

Mark the incorrect statement.

A sphere of radius 1 cm has potential of 8000 V, then energy density near its surface will be

(a) 64

(b) 8

(b) 8

(d) 2.83

The resistance of a galvanometer is 90 ohms. If only 10 percent of the main current may flow through the galvanometer, in which way and of what value, a resistor is to be used

(a) 10 ohms in series	(b) 10 ohms in parallel
(c) 810 ohms in series	(d) 810 ohms in parallel

A uniform electric field pointing in positive x-direction exists in a region. Let A be the origin, B be the point on the x-axis at x = +1 cm and C be the point on the y-axis at y = +1 cm. Then the potentials at the points A, B and C satisfy

(a)

(b)

(c)

(d)