If 100 J of work is done to move electric charge equal to 4 C from a place where potential difference is -10 V to another place where potential is V volt, then the value of V would be:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 15 V
The work done in moving a charge between two points is the charge times the potential difference, \( W = q(V_f - V_i) \), where \( V_i = -10\,\mathrm{V} \) is the starting potential and \( V_f = V \) the final one.
\( 100\,\mathrm{J} = 4\,\mathrm{C}\times\left[V-(-10\,\mathrm{V})\right] \)
\( V+10 = \frac{100}{4} = 25 \)
\( V = 25-10 = 15\,\mathrm{V} \)