NEET2026PhysicsChapterActual
A car battery has an electromotive force of 12 V and an internal resistance of 0.4 . When it is connected to a headlight of resistance 5.6 , what is the potential difference across the terminals of the battery?
Options
- A11.2 V
- B12.8 V
- C12.0 V
- D0.8 V
Correct answer
A. 11.2 V
Step-by-step solution
Given electromotive force E = 12 V , internal resistance r = 0.4 , and external resistance R = 5.6 . The current in the circuit is given by I = E R + r . Substituting the given values, I = 12 5.6 + 0.4 = 12 6.0 = 2 A . The potential difference across the terminals of the battery is V = IR . Substituting the values, V = 2 5.6 = 11.2 V . Answer: 11.2 V