What is happening if energy input remains constant and voltage remains the same in a circuit, but the current decreases?

The resistance of the circuit will definitely increase. This can be proved by the Ohm's Law where it is said that the potential difference across a conductor is directly proportional to the current and the proportionality constant is known as the resistance. The law is expressed as V = IR. As we can see, when the voltage remains constant while the current decreases then the resistance will increase.

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