Assertion (A): Oxide coated cathodes are very commonly used.

Reason (R): Work function of oxide coated cathode is 1 eV whereas it is 4.5 eV for pure tungsten.

1. The effect of feedback is to reduce system error
2. Feedback increases the system gain at one frequency but reduces the system gain as another frequency
3. Feedback can cause an originally stable system to become unstable

Match the following:

1. It is suitable for direction finding application
2. It is a single turn or multiturn coil carrying RF current
3. The loop is surrounded by a magnetic field everywhere perpendicular to the loop

1. To get small size expression.
2. To reduce the number of variables in the given expression.
3. To implement the function of the logic expression with least hardware.
4. To reduce the expression for making it feasible for hardware implementation.