Question

10 joules of work is Done to move a charge of -200 coulomb from point A to B. Which of the two pints is at higher potential? What is the P.D between them. If the points are 4 cm apart what is the component of the electric field parallel to the line joining A and B

Answer 1

Answer:

A is at a higher potential. The potential difference is -0.05 V. The component of the electric field is 1.25 Vm⁻¹

Explanation:

Work done=10J

Charge(q)(W)=-200 C

Now, let potential at A be Vₐ and that at B be Vᵇ.

Now, Uₐ=(-200)Vₐ, Uᵇ=(-200)Vᵇ.

Work done=Difference in potential energies

(-200)Vᵇ-(-200)Vₐ=10

⇒ -200Vᵇ+200Vₐ=10

⇒ Vₐ-Vᵇ=10/200

⇒ Vₐ-Vᵇ=0.05

Since, Vₐ-Vᵇ>0

Hence, Vₐ>Vᵇ.

P.D.=Vᵇ-Vₐ= -0.05 V

Component of electrical field E= -dV/dR

= -(-0.05)/0.04

= 1.25 Vm⁻¹