Statement1: The magnetic filed at the ends of very long current carrying solenoid is half of that at the centre.
Statement2: If the solenoid is sufficiently long, the field within it is uniform.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is true

Answer

B

Explanation

Magnetic field inside a solenoid is `B = mu_(0)ni`.
Magnetic field at the end of a solenoid is `(1)/(2)mu_(0)ni`.
So, the assertion is true. Magnetic field within a sufficiently long solenoid is uniform. So reason is also true. But it does not explain the assertion.