The circuit diagram in the figure below is an amplifier circuit incorporating an operational amplifier (op-amp).
On the figure above, mark, with the letter X, the virtual earth.
In bright sunlight, the light-dependent resistor (LDR) has resistance 
.
Calculate, for the LDR in bright sunlight, the voltmeter reading.
The sunlight incident on the LDR becomes less bright. State and explain the effect on the voltmeter reading of this decrease in brightness.
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