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

Mark out the correct options.

1. Diamagnetism occurs in all materials.
2. Diamagnetism results from the partial alignment of permanent magnetic moment.
3. The magnetizing field intensity H is always zero in free space.
4. The magnetic field of induced magnetic moment is opposite to the applied field.

The capacity of the parallel plate capacitor increases when:

The capacitance in an oscillatory LC circuit is increased by 1%. The change in inductance required to restore its frequency of oscillation is to.

A photo cell is receiving light from a source placed at a distance of 1 m. If the same source is to be placed at a distance of 2 m, then the ejected electron

(a) Moves with one-fourth energy as that of the initial energy

(b) Moves with one-fourth of momentum as that of the initial momentum

(c) Will be half in number

(d) Will be one-fourth in number

Point A is at a lower electrical potential than point B. An electron between them on the line joining them will:

A double convex thin lens made of glass of refractive index 1.6 has radii of curvature 15 cm each.  The focal length of this lens when immersed in a liquid of refractive index 1.63 is

(a) – 407 cm

(b) 250 cm

(c) 125 cm

(d) 25 cm

Our eye is most sensitive for which of the following wavelength

(a) 4500 Å

(b) 5500 Å

(c) 6500 Å

(d) Equally sensitive for all wave lengths of visible spectrum

Substance on the choroid is

(a) Japan black

(b) Nigrim pigment

(c) Carbon black

(d) Platinum black

A paramagnet magnet behaves like a solenoid because both contain currents in the form of:

If angular frequency of an A.C. source used in L-C-R circuit is increased, then inductive reactance __________ and capacitive reactance __________ .