engineering recuitment GATE IN Test Series 2023-24 Mock Test Sensors and Industrial Instrumentation Measurement of PH
A pH electrode, being used at 25°C, has a source resistance of 1010 Ω. The electrode obeys the Nernst equation perfectly. The electronic voltmeter, with which the potential is being measured, has an input impedance of 1011 Ω and a gain of 100. If the pH of the analyte changes form 6.5 to 7.8, the change in voltmeter is
1
Less than 6.8 V
2
between 6.8 V and 7.19 V
3
between 7.2 V and 7.49 V
4
Greater than 7.49 V