Question

If an electron experiences a force equal to its weight when placed in an electric field then intensity of the field will be

Answer 1

............................

Answer 2

The intensity of electric field is  5.57× 10⁻¹¹ V/m.

We know,

F = q×E

where F is the force on the electron,

q is the charge of electron

and E is the electric field.

Again, W = m ×g

where W is the weight of the electron

m is the mass and

g is the acceleration due to gravity.

Given that the electron experiences force equals to its weight, so

F = W

⇒q×E = m ×g

 ⇒ E = (m ×g)/q                            ...(1)

As, m = 9.1 × 10⁻³¹ kg

g = 9.8 m/s²

q = 1.6 × 10⁻¹⁹  C

Putting these values, in eqn. (1), we get:

E = ( 9.1 × 10⁻³¹ × 9.8)/(1.6 × 10⁻¹⁹ ) V/m

  = 5.57× 10⁻¹¹ V/m