KCET · Physics · Electrostatics
A system of two charges separated by a certain distance apart stores electrical potential energy. If the distance between them is increased, the potential energy of the system,
- A may increase or decrease
- B increases in any case
- C remains the same
- D decreases in any case
Answer & Solution
Correct Answer
(A) may increase or decrease
Step-by-step Solution
Detailed explanation
(A)
Potential energy of a system of charges is \(U=\left(\frac{1}{4 \Pi \varepsilon_{0}}\right) \frac{q_{1} q_{2}}{2}\)
In case of like charges, \(\left(q_{1} q_{2}\right)\) is positive
when \(r\) increases, \(U\) decreases
In case of unlike charges, \(\left(q_{1} q_{2}\right)\) is negative
when \(r\) increases, \(|U|\) decreases
but because of negative sign, \(U\) increases.
Potential energy of a system of charges is \(U=\left(\frac{1}{4 \Pi \varepsilon_{0}}\right) \frac{q_{1} q_{2}}{2}\)
In case of like charges, \(\left(q_{1} q_{2}\right)\) is positive
when \(r\) increases, \(U\) decreases
In case of unlike charges, \(\left(q_{1} q_{2}\right)\) is negative
when \(r\) increases, \(|U|\) decreases
but because of negative sign, \(U\) increases.
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