Assertion (A): The conductivity of an n type semiconductor increases with increase in temperature and increase in density of donor atoms.

Reason (R): Diffusion of carriers occurs in semiconductors.

Assertion (A): For a reciprocal microwave junction the S matrix is symmetrical.

Reason (R): In a symmetrical matrix S_ij = S_ji.

1. It is an unpolarised instrument.
2. It has permanent magnet.
3. It has a fixed coil.
4. It has two iron vanes.

1. The mantissa and exponent are separated either by e or E.
2. The mantissa and exponent may have positive or negative sign.
3. Default sign of mantissa is positive.
4. Default sign of exponent is negative.