Wave Optics — Physics STD 12 Science — Question

For a glass prism, the angle of minimum deviation will be smallest for the light of

Two similar spheres having +q  and -q charge are kept at a certain distance. F force acts between the two. If in the middle of two spheres, another similar sphere having +q charge is kept, then it experience a force in magnitude and direction as

(a) Zero having no direction	(b) 8F towards +q  charge
(c) 8F towards -q  charge	(d) 4F towards +q  charge

In a region of constant potential:

The current sensitibility of a moving coil galanometer increases with decrease in:

A particle of charge q and mass m is moving along the x -axis with a velocity v and enters a region of electric field E and magnetic field B as shown in figure below for which figure the net force on the charge may be zero

(a)

(b)

(c)

(d)

A ray of light propagates from glass (refractive index = 3/2) to water (refractive index = 4/3).  The value of the critical angle

(a) sin–1(1/2)

(b)

(c)

(d)

A parallel plate capacitor has a capacity C. The separation between the plates is doubled and a dielectric medium is introduced between the plates. If the capacity now becomes 2C, the dielectric constant of the medium is

(a) 2

(b) 1

(c) 4

(d) 8

The width of forbidden energy gap in the semiconductor is approximately :

Magnets A and B are geometrically similar but the magnetic moment of A is twice that of B. If T₁ and T₂ be the time periods of the oscillation when their like poles and unlike poles are kept together respectively, then  will be

(a)

(b)

(c)

(d)

Conductivity of semiconductors: