Question

In a Millikan oil-drop experiment (Section 22-8), a uniform electric field of 5.78 x 105 N/C is maintained in the region between two plates separated by 8.56 cm. Find the potential difference (in V) between the plates.

Answer 1

The required potential difference is
`4.95 * 10^(4)~V`.

Step-by-step explanation:

We know, electric field is nothing but the negative gradiant of potential. Mathematically, in three-dimension,

`\vec{E} = -\vec{\\abla}V`

In one dimension, the magnitude of the electric field is

`E = (V)/(x)`

where '
`V`' is the applied voltage and '
`x`'is the distance through which the voltage is applied.

Given,
`V = 5.78 * 10^(5)~N~C^(-1)~ and~ x = 8.56~cm = 0.0856~m`.

So the required potential difference is

`V = E * x = 5.78 * 10^(5)~N~C^(-1) * 0.0856~m = 4.95 * 10^(4)~V`