Question

The work done in rotating an electric dipole in an electric field:
(a) W = ME (1 – cos θ)
(b) W = ME tan θ
(c)W = ME sec θ
(d) None

Answer 1

Answer:

(a) W = ME (1_cos 0)

Explanation:

step by step explanation

Answer 2

The correct answer is option (a) W = ME(1-cosθ).

Given,

An electric dipole and a uniform electric field.

To Find,

The work done in rotating an electric dipole in an electric field.

Solution,

Let there be an electric dipole of charge +q and -q and the distance between the poles is 2r.

Now, the torque required to rotate the dipole is

τ = MEsinθ

Let us assume that the dipole is rotated dθ

Now,

W = $\int\limits^t_0$MEsinθdθ, where t is θ

W = ME[cos0 - cos θ}

W = ME(1-cosθ)

Hence, the work done in rotating an electric dipole in an electric field is ME(1-cosθ).

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