Electrons moving with different speeds enter a uniform magnetic field in a direction perpendicular to the field. They will move along circular paths.

Given below are two statements: One is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: In a uniform magnetic field,speed and energy remain the same for a moving charged particle.
Reason $(R)$: $A$ moving charged particle experiences a magnetic force perpendicular to its direction of motion.

Consider the following statements regarding a charged particle in a magnetic field. Which of the statements are true?

The figure shows three situations when an electron with velocity $\vec v$ travels through a uniform magnetic field $\vec B$. In each case,what is the direction of the magnetic force on the electron?

$A$ charged particle moves through a magnetic field in a direction perpendicular to it. Then the

$A$ current-carrying long solenoid is placed on the ground with its axis vertical. $A$ proton is falling along the axis of the solenoid with a velocity $v$. When the proton enters into the solenoid,it will