Read the following statements and choose the correct option: Assertion (A):…
2023
Read the following statements and choose the correct option:
Assertion (A): Electric current is a vector quantity.
Reason (R): Electric current is a quantity having magnitude as well as direction.
- A.
(A) is true, but (R) is false.
- B.
Both (A) and (R) are true, but (R) is not the correct explanation of (A).
- C.
(A) is false, but (R) is true.
- D.
Both (A) and (R) are true and (R) is the correct explanation of (A).
Show answer & explanation
Correct answer: C
A physical quantity is classified as a vector only when, besides having a magnitude and a specific direction, it also obeys the vector (parallelogram) law of addition; possessing magnitude and direction together is a necessary condition for a vector but is not, by itself, sufficient.
Electric current has a defined magnitude (measured in amperes) and is conventionally assigned a direction — the direction of flow of positive charge in a circuit.
Kirchhoff's Current Law states that currents meeting at a junction combine by simple algebraic (scalar) addition — the sum entering equals the sum leaving — not by the parallelogram rule used to combine true vector quantities.
Because current does not obey the vector law of addition despite carrying a magnitude and a direction, it is classified as a scalar quantity in circuit theory.
Assertion (A), which claims current is a vector quantity, is therefore false.
Reason (R), which only states that current has magnitude as well as direction, is a true statement about the properties current carries — even though this property alone does not make it a vector.
Cross-check: a genuine vector such as velocity combines according to the parallelogram law, whereas two currents of, say, 3 A and 4 A meeting at a junction simply add to 7 A rather than combining geometrically — this contrast confirms why current is classified as scalar despite having a direction.
Since (A) is false and (R) is true, the correct choice is: (A) is false, but (R) is true.