A proton enters a region of uniform magnetic field of magnitude
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A proton enters a region of uniform magnetic field of magnitude 5.0mT. The velocity of the proton makes an angle of 40∘ with the direction of the field.
(i) Calculate the magnitude of the magnetic force acting on the proton if its speed is 2.0×106ms−1.
(ii) The proton now enters the same field at the same angle but with its speed reduced to one-half of the original value. Find the new magnitude of the force.
(iii) If, instead of changing the speed, the proton were to enter the field at 90∘ while maintaining the original speed of 2.0×106ms−1, by what factor would the force calculated in part (i) change? Justify your answer briefly.