42 - Magnetism Questions Answers

In a region of space, a uniform electric field 𝐸⃗⃗⃗ , uniform magnetic field 𝐵⃗⃗⃗ and  
uniform gravitational field 𝑔⃗ exist in mutually perpendicular direction. A charged particle is  
moving with uniform velocity in this region. Once the particle leaves this region and another  
where there is only 𝑔⃗ , its speed begins to decrease. How long after leaving the first region  
does the velocity of particle reach the minimum value?

Answer : t=E/Bg

An electron originates at a point A lying on the axis of a straight solenoid and moves with a velocity v at an angle α to the axis. The magnetic induction of the field is B. Find the distance r from the axis to the point on the screen into which the electron strikes. The screen is oriented at right angles to the axis and is located at a distance l from the point A.

Thanks in advance sir.