Electric Charges and Fields — Physics STD 12 Science — Question

To obtain maximum EMF from a number of cells, they must be connected in.

50% of the X-ray coming from a Coolidge tube is able to pass through a 0.1mm thick aluminium foil. The potential difference between the target and the filament is increased. The thickness of the aluminium foil that will allow 50% of the X-ray to pass through will be:

A radioactive nucleus emits a beta particle. The parent and daughter nuclei are

(a) Isotopes

(b) Isotones

(c) Isomers

(d) Isobars

Pick the correct options.

1. All electrons have magnetic moment.
2. All protons have magnetic moment.
3. All nuclei have magnetic moment.
4. All atoms have magnetic moment.

The number of turns in a coil of wire of fixed radius is 600 and its self inductance is 108mH. The self inductance of a coil of 500 turns will be:

A solenoid is 1.5 m long and its inner diameter is 4.0 cm. It has three layers of windings of 1000 turns each and carries a current of 2.0 amperes. The magnetic flux for a cross-section of the solenoid is nearly

(a) 2.5 × 10–7 weber

(b) 6.31 × 10–6 weber

(c) 5.2 × 10–5 weber

(d) 4.1 × 10–5 weber

Current density is a __________.

The relaxation time in conductors

(a) Increases with the increase of temperature

(b) Decreases with the increase of temperature

(c) It does not depend on temperature

(d) All of sudden changes at 400 K

ike magnetic force ______ each other.