Question

(
121. In Thomson's experiment for the
measurement of mof an cloctron is 10%
Vm and the magnetic field is 10 T. The
beam was originally accelerated
through a potential difference of 285
V. The value of specific charge of
electron will be
125
(1) 1.67 x 10" Ckg
(2) 1.47x 10" Ckg
(3) 1.74x 10" Ckg
ther​

Answer 1

ANSWER

B=10

−2

Wb/m

2

So, from Potential difference and distance, E=

0.5

500×10

3

=10

5

V/m

So, for Magnetic field force =qVB------------------ (I)

The force due to electric field =qE---------------(II)

Equating (I) and (II) acting in opposite directions,

qVB=qE

⇒10

5

=10

−2

×V⇒V=10

7

m/s