The length of a potentiometer wire is 600 cm and it carries a current of 40 mA. For a cell of emf 2V and internal resistance 10Ω, the null point is found to be at 500 cm. On connecting a voltmeter across the cell, the balancing length is decreased by 10 cm.
The voltmeter reading will be
(a) 1.96 V
(b) 1.8 V
(c) 1.64 V
(d) 0.96 V