Question

For testing appliances the wattage of test lamp should be
A. very low
B. low
C. high
D. any value

Answer 1

Hint: Wattage is the amount of electric power expressed in watts.
It is the amount of work done or electricity consumed per unit time.

Formula Used: In terms of resistance, power can be expressed as
$P = {I^2} \times R$
Where $R$ is the resistance, $P$ is the power and $I$ is the current through the resistance.

Complete step by step answer:
Wattage is the amount of electric power expressed in watts.
It is the amount of work done or electricity consumed per unit time. 1 watt is 1 joule per second.
Power is also defined as the product of current and voltage. It is given by the equation
$P = V \times I$
Where $V$ is the voltage and $I$ is the current. In terms of resistance power can be expressed as
$P = {I^2} \times R$
Where $R$ is the resistance.
We know that resistance is the obstruction to the flow of current. So, if resistance is small then more current flows through the circuit and power will be high. If resistance is a large then less current flows through the circuit and thus power will be less.
The test lamp is used for testing appliances. It should have a low resistance so that it will not blow up the testing appliance. Lower resistance of the test lamp means it should have high wattage.
Hence, the correct answer is option (c).

Note: The term wattage should not be confused with voltage. Wattage is a term used to express the electrical power. It is the electrical energy consumed per unit time.