Assertion : The magnetic field at the ends of a very long current carrying solenoid is half of that at the centre.
Reason : 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 and 'R' is not the correct explanation of 'A'
C. 'A' is true and 'R' is false
D. 'A' is false and 'R' is false

Answer

B