Join 60,000+ competitive exam aspirants
The work done in moving a charge +Q across two points having a potential difference K is:
QK
2QK
4QKтАЛ
2QKтАЛ
QK
The work done in moving a charge across two points in an electric field is equal to the product of the magnitude of the charge and the potential difference between those two points. Mathematically, W=Q├ЧV (or QK), where Q is the charge and K is the potential difference.
The work done in moving a charge across two points in an electric field is equal to the product of the magnitude of the charge and the potential difference between those two points. Mathematically, W=Q├ЧV (or QK), where Q is the charge and K is the potential difference.
Moving a charge through a potential difference is similar to lifting an object of mass m to a certain height against gravity. The work done depends on both the size of the mass and the gravitational potential difference (height).
Remember 'Work = Charge ├Ч Voltage' or simply W = QV (or QK).
W=Q├ЧV тАФ Work done equals charge multiplied by potential difference
V=QWтАЛ тАФ Definition of electric potential difference
Electric potential difference (V or K) between two points is defined as the work done (W) per unit positive test charge (Q) in moving it from one point to the other against electrostatic forces: V=QWтАЛ Rearranging this formula for work done gives: W=Q├ЧV Substituting V=K, we get $$W = QK$.
Work done is independent of the path taken between two points in an electrostatic field (conservative force).
The SI unit of work done is Joule (J) or Electron-volt (eV).
Potential difference K is measured in Volts (V).
Fundamental relation for calculating electrostatic energy changes.
Assumes uniform or defined potential difference between the points.
Calculating kinetic energy acquired by charged particles in particle accelerators.
Determining energy stored in capacitors and electrical circuits.
Option A (QK) is correct because W=Q├ЧPotential┬аDifference.
Options B, C, and D introduce incorrect factors such as 2, 1/4, or 1/2 which are dimensionally inconsistent.
A is correct тАФ The work done in moving a charge +Q across a potential difference K is given by W = QK.
Always check the units: Charge (Coulombs) ├Ч Potential Difference (Volts) = Energy (Joules).