Question

The electrons are emitted from cathode and accelerated to anode. If the kinetic energy acquired by each electron is 6.4 x 10-16 J, then potential difference between the cathode and anode is: a) 8 x 10 V b) 1.3 x 10'y c) 2.5 x 10-V d) 4 x 10 V​

Answer 1

Answer:

(a)Kinectic energy of electron = eV

also, eV=

2

1

mv

2

⇒v=

2eV/m

−(1)

also, BeV=mv

2

/r

⇒r=mV/Be

using equation, (1),r=1 mm

(b)θ=30

o

v

1

=vsinθ

r

1

=mvsinθ/Be=0.5mm