Lamps will have ratings for both ? and ?.

Lamps will have ratings for both ? and ?.

• A. Current / Resistance
• B. Voltage / Power
• C. Resistance / Voltage
• D. Voltage / Current

Answer: (B)

The key idea is that lamps are specified by the voltage they require and the power they consume. The voltage rating tells you the supply level the lamp is designed to run at, ensuring safe and reliable operation. The power (wattage) rating indicates how much energy the lamp uses at that voltage, which also relates to brightness and heat. Current and resistance aren’t fixed ratings you typically rely on for a lamp: current is determined by power and voltage (current = power/voltage), and resistance changes with temperature as the filament heats up. So, knowing the voltage and power lets you understand both how it should be powered and how bright it will be, making them the standard ratings.

The key idea is that lamps are specified by the voltage they require and the power they consume. The voltage rating tells you the supply level the lamp is designed to run at, ensuring safe and reliable operation. The power (wattage) rating indicates how much energy the lamp uses at that voltage, which also relates to brightness and heat. Current and resistance aren’t fixed ratings you typically rely on for a lamp: current is determined by power and voltage (current = power/voltage), and resistance changes with temperature as the filament heats up. So, knowing the voltage and power lets you understand both how it should be powered and how bright it will be, making them the standard ratings.