In the circuit shown, the ammeter reads 1 ampere and voltmeter 10 volts. The internal resistance of the ammeter is 1 ohm and that of voltmeter is 50 ohms. The value of R is _______.

(a) 111 .2 ohms
(b) 120 ohms
(c) 100 ohms
(d)    112 ohms

Ans: D