The electric field strength between a parralel plate is E. The separation of plate is doubled and potential difference between the plate is increased by factor of 4. What is new electric field strength

The new electric field strength is 2E

Explanation:

The electric field between parallel plated can be calculated from the formula

E = V/d

Where E is the Electric field strength

V is the potential difference between the plates

and d is the separation between them

In the first instance where the electric field strength between the parallel plates is E. Let the potential difference (V) be V₁ and the separation between the plates (d) be d₁.

∴ E = V₁/d₁

Now, from the question

The separation of plate is doubled, that is, d = 2d₁

and potential difference between the plate is increased by factor of 4, that is, V = 4V₁

Then,

From E = V/d

Let the new electric field be E₂

Then,

E₂ = 4V₁/2d₁ = 2V₁/d₁

E₂ = 2(V₁/d₁)

E₂ = 2E

Hence, the new electric field strength is 2E.