Which of the following statements are correct ?
A. The angle at minimum deviation of a prism is greater for violet light than that for red light.
B. The purpose of microscopes and telescopes is to increase the visual angle.
C. For the diffraction to take place the size of aperture or of the obstacle should be comparable to the wavelength of light.
D. The light scattered in the direction of the incident light is always plane polarised.
E. The source and its virtual image can behave as a coherent sources.
Choose the correct answer from the options given below:

Two wires of copper have lengths \( L \) and \( 2L \) and cross sectional area \( 2A \) and \( A \), respectively. The ratio of their specific resistance would be-

A proton, a deuteron and an alpha particle have the same kinetic energy and move in a uniform magnetic field perpendicular to their direction of motion. The ratio of the radii of their circular paths is :

The refractive index of an equilateral prism is \( \sqrt{3} \). The angle of incidence for which angle of deviation is minimum is :

Two inductor coils of self inductance \( L_1 \) and \( L_2 \) having same length and same area of cross-section are placed so close that effective flux in one coil is completely linked with the other. The mutual inductance between them is, is equal to:

The shortest wavelength present in the Lyman series of spectral lines is : (Given Rydberg constant \( R = 1.097 \times 10^7 \text{ m}^{-1} \))

The electric field and magnetic field of a plane electromagnetic wave propagating in vacuum are expressed as
\(E_x=E_0 \sin (k z-\omega t)\)
\(B_y=B_0 \sin (k z-\omega t)\)
Which of the following statements are correct?
(A). The wave is propagating along the z- direction.
(B). The electric field Ex and magnetic field By are perpendicular to each other and perpendicular to the z direction.
(C) The electric and magnetic fields Ex and By are perpendicular to each other, and parallel to the direction of propagation.
(D) k is related to the wave length À of the wave by the usual equation \(k = A / 2 Tt\)
Choose the correct answer from the options given below:

The critical angle is maximum when light travels from

A plane electromagnetic wave of frequency 25 GHz is propagating in vacuum along the z-direction. At a particular point in space and time, the magnetic field is given by a value \(5 \times 10^{-8} \text{ T}\) along Y-direction. The corresponding electric field is (speed of light \(c = 3 \times 10^8 \text{ m/s}\))

Germanium is a semiconductor because:

The radii of curvature of a double convex lens are 15 cm and 10 cm and its refractive index is 1.3. Its focal length will be:

The solution of the differential equation \(2 x \frac{d y}{d x}-y=3\) represents a family of :

There are two metallic spheres A and B having radii equal to R and 2R respectively. A charge Q is distributed on these two spheres such that the two spheres have equal surface charge densities. The ratio of charge on A to charge on B is :