Circuit with Internal Resistance · PhysicsBowl 2010 #27
Physics · electromagnetism
Problem
The circuit shown contains a battery (of emf Vbat) with an internal resistance r connected to a rheostat (variable resistor). When the resistance of the rheostat is increased, which of the following statements is true?
[Figure: Circuit diagram with battery, internal resistance, and rheostat]
(A) The terminal voltage (Va−Vb) increases.
(B) The current through the ammeter in the circuit increases.
(C) The power associated with the internal resistance increases.
(D) The potential difference across the rheostat decreases.
(E) None of the above statements is true.