There are 50 turns / cm in a long solenoid. If 4 Amp current is flowing in the solenoid, the approximate value of mag. field along its axis at an internal point and one end will be respectively.
Options:
(a) `12.6xx 10^(-3)` Tesla ; `6.3xx10^(-3)` tesla
(b) `12.6xx 10^(-3)` Tesla ; `25.1xx10^(-3)` tesla
(c) `25.1xx 10^(-3)` Tesla ; `12.6xx10^(-3)` tesla
(d) `25.1xx 10^(-3)` Tesla ; `6.3xx10^(-3)` tesla