A potential divider circuit is designed to detect the difference in temperature between two different places.
The cell has electromotive force (e.m.f.) 
and negligible internal resistance. Initially, thermistors X and Y are at the same temperature and have the same resistance. The voltmeter reads 
. X is then placed in a cold environment and its resistance doubles. Y is placed in a warm environment and its resistance halves. What is the new reading on the voltmeter?
