Which of the following statement(s) is/are incorrect?

(A) The Kirchhoff's laws are equally applicable in alternating current circuit and direct current circuits,
(B) It is not necessary that the wire stretched on the meter bridge must have a uniform cross-sectional area.
(C) The internal resistance of the cell does not affect the reading of the null point in metre bridge.
(D) Electrical potential has no direction, the electrical potential gradient has a direction.

(B) only

The correct answer is Option (2) → (B) only

(A) Correct — Kirchhoff's laws apply to both AC and DC circuits.

(B) Incorrect — For accurate measurements, the wire on a metre bridge must have uniform cross-section; otherwise, null point will be inaccurate.

(C) Correct — At null point, no current flows through galvanometer, so internal resistance of cell does not affect it.

(D) Correct — Electric potential is a scalar (no direction), while potential gradient has direction.

Incorrect statement: (B)