Question

Which of the following quantity is a scalar?

• A. Current
• B. Weight
• C. Velocity
• D. Force

Answer 1

The correct option is A

Current

Scalar quantity - A quantity that has only magnitude and no direction is called a scalar quantity.

Vector quantity - A quantity that has both magnitude and direction is called a vector quantity.

Vectors obey the law of vector addition

Explanation of correct answer

Option A,

1. Current is the rate of flow of electric charge.
2. It has both magnitude and direction.
3. But it does not obey the law of vector addition.
4. Therefore, it is a scalar quantity.

Option A is correct

Explanation of incorrect answer

Option B,

1. Weight is the force applied on earth by a body.
2. It is always downward.
3. So it has direction.
4. It also obeys the law of vector addition.
5. Therefore, it is a vector quantity.

Option B is incorrect

Option C,

1. Velocity is the rate of change of displacement.
2. Since displacement is a vector quantity and time is a scalar, displacement divided by time is a vector quantity.

Option C is incorrect

Option D,

1. Force is the product of mass and acceleration.
2. Since acceleration is a vector and mass is a scalar, force is a vector quantity.

Option D is incorrect.

Therefore, option A is correct.