Wave Optics — Physics STD 12 Science — Question

A triangular prism of glass is shown in the figure. A ray incident normally to one face is totally reflected, if θ = 45° . The index of refraction of glass is

(a) Less than 1.41

(b) Equal to 1.41

(c) Greater than 1.41

(d) None of the above

A ring of radius R, made of an insulating material carries a charge Q uniformly distributed on it. If the ring rotates about the axis passing through its centre and normal to plane of the ring with constant angular speed ω, then the magnitude of the magnetic moment of the ring is

(a) Qω

(b)

(c) Q

(d)

During the 19th century, light was considered to be a stream of particles called:

A current i passes through a wire of length l, radius of cross-section r and resistivity r. The rate of heat generation is

(a)

(b)

(c)

(d) ilρ/r

Which of the following statements is not correct according to Rutherford model?

The power of two convex lenses A and B are 8 diopters and 4 diopters respectively. If they are to be used as a simple microscope, the magnification of

(a) B will be greater than A	(b) A will be greater than B
(c) The information is incomplete	(d) None of the above

Light energy emitted by stars is due to

(a) Breaking of nuclei	(b) Joining of nuclei
(c) Burning of nuclei	(d) Reflection of solar light

Before the saturation state of a diode at the plate voltages of 400 V and 200 V respectively the currents are i₁ and i₂ respectively. The ratio i₁/i₂ will be

(a)

(b) 2

(c) 2

(d) 1/2

A galvanometer whose resistance is  120 Ω gives full scale deflection with a current of 0.05 A so that it can read a maximum current of 10 A. A shunt resistance is added in parallel with it. The resistance of the ammeter so formed is

(a) 0.06 Ω

(b) 0.006 Ω

(c) 0.6 Ω

(d) 6 Ω s