Fuses and circuit breakers carry a rating that tells what they protect against. In which unit is that rating given?
AIn volts (V)
BIn amperes (A)
CIn watts (W)
DIn ohms (Ω)
Answer & Solution
Correct answer: B. In amperes (A)
1. Fuses and circuit breakers are rated in amperes, the SI unit of current.
2. They open the circuit when a sustained current exceeds safe limits, so current is the quantity that matters.
3. Many electrical appliances carry ampere ratings as well.
4. Volts measure the supply and watts measure power, but the device trips on the current flowing through it, not on either of those.
_Source: OpenStax College Physics (CC BY 4.0), Ch 20 "Electric Current, Resistance, and Ohm's Law", section 20.1 Current_
Keep practising Electric Current, Resistance, and Ohm's Law
Browse all Electric Current, Resistance, and Ohm's Law questions for ASVAB, or explore more Physics topics.
Related questions
Sort AC from DCA 1200-W toaster runs for 1 minute to make a slice of toast. How much electrical energy doMany electrical safety rules set the maximum allowed shock current at which value?Worn insulation lets a short circuit form across 240-V AC through a resistance of just 0.2A technician standing on a rubber mat has a total resistance of 300 kilohms. What current A 500-W room heater runs on 120-V AC power. What peak current does it draw?A wall outlet in a house supplies current that repeatedly reverses its direction of flow. A cheap extension cord made with thinner wire has a resistance of 0.300 ohm. How much powe