A proton moves at a constant speed v along the x-axis through a crossed electric and magnetic field. The magnetic field is B = B₀ k T. The electric field E in V/m is

Step-by-step solution

Velocity of the proton, v = v i Magnetic field, B = B₀ k For the proton to move at a constant velocity, the net force acting on it must be zero. Lorentz force, F = q( E + v B ) = 0 E = -( v B ) E = -(v i B₀ k ) E = -vB₀( i k ) Since i k = - j E = -vB₀(- j ) = vB₀ j Answer: vB₀ j