Electronics — Physics STD 12 Science — Question

The vecter term of coulomb's law is :

A metal block is exposed to beams of X-ray of different wavelength. X-rays of which wavelength penetrate most?

The core of a transformer is laminated to reduce energy losses due to(a) Eddy currents(b) Hysteresis(c) Resistance in winding(d) None of these

A) Line spectra is due to atoms in gaseous state:
B) Band spectra is due to molecules:

Assertion  :   A direct current flows through a metallic rod, produced magnetic field only outside the rod.
Reason     : There is no flow of charge carriers inside the rod.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Force between the two parallel wires carrying currents has been used to define:

Two non-ideal batteries are connected in parallel. Consider the following statements:

1. The equivalent emf is smaller than either of the two emfs.
2. The equivalent internal resistance is smaller than either of the two internal resistances.

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