An electron in a TV picture tube moves horizontally with a speed 2 ×

1.	An electron in a TV picture tube moves horizontally with a speed 2 × 107 m/s. It is deflected upward by a horizontal magnetic field of induction 10-3 T. Find the magnitude of the force acting on the electron due to the action of the magnetic field.
Answer» Data : e = 1.6 × 10^-19 C, v = 2 × 10⁷ m/s, B = 10^-3 T The magnitude of the magnetic force, F_m = evB (∵\(\vec v\)⊥ \(\vec B\)) = (1.6 × 10^-19 C)(2 × 10⁷m/s) (10^-3 T) = 3.2 × 10^-15 N = 3.2 fN

An electron in a TV picture tube moves horizontally with a speed 2 × 107 m/s. It is deflected upward by a horizontal magnetic field of induction 10-3 T. Find the magnitude of the force acting on the electron due to the action of the magnetic field.

Answer»

Data : e = 1.6 × 10^-19 C,

v = 2 × 10⁷ m/s,

B = 10^-3 T

The magnitude of the magnetic force,

F_m = evB (∵\(\vec v\)⊥ \(\vec B\))

= (1.6 × 10^-19 C)(2 × 10⁷m/s) (10^-3 T)

= 3.2 × 10^-15 N = 3.2 fN