A potential divider circuit is designed to detect the difference in temperature between two different places. [Figure showing a potential divider circuit with thermistors X and Y and a voltmeter] The cell has electromotive force (e.m.f.) 20 mV and negligible internal resistance. Initially, thermistors X and Y are at the same temperature and have the same resistance. The voltmeter reads 10mV. 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?

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