Resistance + Voltage in a LDR?

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With an LDR (Light dependent resistor), I understand that as light intensity increases, the resistance decreases.

However I do not understand how as light intensity increases, VOLTAGE also falls with resistance falling.

Please explain to me why VOLTAGE falls with resistance falling when the light intensity increases for an LDR.


Posted Sat 21st April, 2012 @ 19:03 by krissh

1 Answer

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I think your refering to the potential difference across the LDR. If a component has a high resistance, the potential difference (voltage) across it is also high because the resistance means that energy is lost, so you might have 6V going in and 1V coming out. If the resistance is low, there is a smaller potential difference because less energy is lost across the component, so you might have 6V going in and 5V coming out.

Hope that helps!

Answered Wed 25th April, 2012 @ 09:04 by Tree