Question

What is the work done in bringing a charge of 3m C through a potential difference of 4000 V

Answer 1

Given :

• Charge, Q = 3 m C
• Potential difference, V = 4000 V

To find :

• Work done , W = ?

Knowledge required :

• W = V Q

( where W is work done in joule , V is potential difference in volts and Q is charge in coulomb )

• 1 C = 1000 m C

there are 1000 mili-coulombs in 1 coulomb.

Calculation :

Given that,

→ Q = 3 m C

→ Q = 3 / 1000  C

→ Q = 0.003 C

Now,

Using formula

→ W = V Q

→ W = (4000) × (0.003)

→ W = 12 J

therefore,

Work done in moving 3 mC of charge through a potential difference of 4000 V is 12 Joules.

Answer 2

Given ,

• Charge (q) = 3 mc
• Potential difference (v) = 4000 volt

We know that ,

The work done to move a unit charge from one point to another point is called potential difference

It is denoted by " v "

$\boxed{ \sf{v = \frac{w}{q}} }$

The SI unit of potential difference is " volt "

Thus ,

4000 = w ÷ [3 × (10)^(-3)]

w = 4000 × 3 × (10)^(-3)

w = 12 joule

$\therefore\underline{ \sf{The \: work \: done \: is \: 12 \: J}}$