Question

An electron initially at rest falls a distance of 1.5 cm in a uniform electric field of magnitude 2×10⁴ N/C .The time taken by the electron to fall thus distance is​

Answer 1

Answer:

In figure the field is upward. So the negatively charged electron experiences a downward force.

∴ The acceleration of electron is

a

e

=

m

e

eE

The time requried by the electron to fall through a distance h is

t

e

=

(

a

e

2h

)

=

eE

2hm

e

[using (i)]

=[

1.6×10

−19

×2×10

4

2×1.5×10

−2

×9.11×10

−31

]

1/2

=2.9×10

−9

solution