The potential difference between the terminals of a battery of emf = 10 V and internal resistance 1 Ohm drops to 9.8 V when connected accross an external resistance. The resistance of the external resistor is

(A) 49 Ohm

(B) 25 Ohm

(C) 31 Ohm

(D) 43 Ohm

Answer is 49 Ohm Because Voltage across the internal resistor is 10-9.8=0.2V Current through the circuit is 0.2/1 =0.2 Amperes. Voltage across the External resistor is 9.8V Resistance of External Resistor is = 9.8/0.2 =49 Ohm. It is easiest way Was this answer helpful9

Answer is 49 Ohm Because Voltage across the internal resistor is 10-9.8=0.2V Current through the circuit is 0.2/1 =0.2 Amperes. Voltage across the External resistor is 9.8V Resistance of External Resistor is = 9.8/0.2 =49 Ohm. It is easiest way Was this answer helpful>>>✓subhajit maji [IITB]