Reading P = V squared / R for a fixed supply voltage, what happens as the connected resistance falls?
APower stays fixed by the supply alone
BPower falls as the voltage rises
CPower rises as resistance falls
DPower falls as resistance falls
Answer & Solution
Correct answer: C. Power rises as resistance falls
1. In P = V squared / R the resistance sits in the denominator.
2. Holding V fixed and shrinking R therefore makes P larger.
3. So the lower the resistance connected across a given supply, the greater the power delivered.
4. This is why a near-zero resistance path across a supply dissipates a dangerous amount of power.
5. Option four inverts the dependence and would predict that a short circuit is harmless.
_Source: OpenStax College Physics (CC BY 4.0), Ch 20 "Electric Current, Resistance, and Ohm's Law", section Power in Electric Circuits_
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