Electromagnetic Waves — Physics STD 12 Science — Question

X-rays are known to be electromagnetic radiations. Therefore the X-ray photon has

(a) Electric charge

(b) Magnetic moment

(c) Both electric charge and magnetic moment

(d) Neither electric charge nor magnetic moment

The angle of dip at a place on the earth gives

(a) The horizontal component of the earth's magnetic field

(b) The location of the geographic meridian

(c) The vertical component of the earth's field

(d) The direction of the earth's magnetic field

The electric field due to a uniformly charged sphere of radius R as a function of the distance from its centre is represented graphically by

(a)

(b)

(c)

(d)

The fundamental frequency of a string is proportional to:

1. Inverse of its length.
2. The diameter.
3. The tension.
4. The density.

In the figure shown, for an angle of incidence 45°, at the top surface, what is the minimum refractive index needed for total internal reflection at vertical face

(a)

(b)

(c)

(d)

Mutual inductance of a system of two coil does not depend on ___________ .

The maximum kinetic energy of a photo electron emitted from a metal is 1.8 eV . The value of stopping potential (cut-off voltage) will be :

A person wears glasses of power – 2.0 D. The defect of the eye and the far point of the person without the glasses will be

(a) Nearsighted, 50 cm

(b) Farsighted, 50 cm

(c) Nearsighted, 250 cm

(d) Astigmatism, 50 cm

A monochromatic beam of light falls on YDSE apparatus at some angle (say q) as shown in figure. A thin sheet of glass is inserted in front of the lower slit S₂. The central bright fringe (path difference = 0) will be obtained

(a) At O

(b) Above O

(c) Below O

(d) Anywhere depending on angle q, thickness of plate t and refractive index of glass m

A non-conducting solid sphere of radius R is uniformly charged. The magnitude of the electric field due to the sphere at a distance r  from its centre

(a) Increases as r increases for r < R	(b) Decreases as r  increases for 0 < r < ∞
(c) Decreases as r  increases for R < r < ∞	(d) a, c