Find the magnitude of the force on an electron that is travelling with velocity 2 x 10^4 ms^(-1) in the x direction through a uniform magnetic field of strength 2T in the y direction.

This question tells us we only need to consider the magnitude of the force, and since the magnetic field and electron's velocity are perpendicular, we can simply use the equation

F = Bqv.

We have B = 2 T, q = 1.6 x 10-19 C (the charge of an electron) and v = 2 x 104 ms-1.

Substituting these values into the equation gives 

F = 2 * (1.6  x 10-19 ) * (2 x 104) = 6.4 x 10-15 N   (Remember your units!)

SH

Related Physics A Level answers

All answers ▸

a solar cell of area 2m^2 has maximum a power output per unit area of 20W/m^2 . if four solar cells are used together at once, how much energy is release in 2 mins at max power output?


If f(x)= ln(x^2)-4, give f^-1(x)


If a ball is thrown on the Moon, the projectile would have a greater range than if it were to have been thrown on Earth. Why is this the case?


Two immobile point charges Q1 and Q2 of values +q and +3q respectively are some distance apart. Q3, with value +2q is placed between them and does not move. What is the ratio of the distance between Q3 and Q2 to the distance between Q1 and Q3?