Does a power failure in a resistor on a parallel/series circuitry create a complete circuit? Explain.

Thermal radiation gets its name because

An electron moving at 5.06 103 m/s in a 1.23 t magnetic field experiences a magnetic force of 1.40 10-16 n. what angle does the velocity of the electron make with the magnetic field? there are two answers between 0° and 180°. (enter your answers from smallest to largest.)

How do i solve this physics problem?