Question

20. In a coolidge tube the potential difference between
cathode and anode is 200 kV and the distance between
them is 20 cm. Calculate the intensity of the electric
field in the tube.
Ans. 10 V m-​

Answer 1

As we know, Potential difference V and electric field  E are related as

$E= -\frac{V}{l}$

where negative sign implies direction and l is length.

Taking the magnitude,

$E = \frac{200 * 10^3}{20 * 10^{-2}}$

E =  10⁶ V/m

This is the answer.