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

A thin rod of length f/3  lies along the axis of a concave mirror of focal length f.  One end of its magnified image touches an end of the rod. The length of the image is

(a) f

(b)

(c) 2f

(d)

A transformer has turn ratio 100/1. If secondary coil has 4 amp current then current in primary coil is

(a) 4 A

(b) 0.04 A

(c) 0.4 A

(d) 400 A

A dip circle is at right angle to the magnetic meridian. What will be the apparent dip

(a) 0°

(b) 30°

(c) 60°

(d) 90°

The direction of magnetic lines of forces close to a straight conductor carrying current will be

(a) Along the length of the conductor

(a) Along the length of the conductor

(c) Circular in a plane perpendicular to the conductor

(d) Helical

Diffraction of light can be explained by the following:

Consider the following two statements:

1. Line spectra contain information about atoms.
2. Band spectra contain information about molecules.

1. Both A and B are wrong
2. A is correct but B is wrong.
3. B is correct but A is wrong
4. Both A and B are correct.

In a Young's double slit experiment, the fringe width is found to be 0.4 mm. If the whole apparatus is immersed in water of refractive index 4/3 without disturbing the geometrical arrangement, the new fringe width will be

(a) 0.30 mm

(b) 0.40 mm

(c) 0.53 mm

(d) 450 micron

A moving charge will gain energy due to the application of

(a) Electric field

(b) Magnetic field

(c) Both of these

(d) None of these