213k views
5 votes
A small bulb is rated at 7.5 W when operated at 125 V. Its resistance (in ohms) is : (a) 17 (b) 7.5 (c) 940 (d) 2100 (e) 0.45

User Nandal
by
8.2k points

1 Answer

6 votes

Answer:

Resistance of the bulb is 2100 watts.

Step-by-step explanation:

Given that,

Power of the bulb, P = 7.5 watts

Voltage, V = 125 volts

We have to find the resistance of the bulb. The power of an electrical appliance is given by the following formula as :


P=(V^2)/(R)


R=(V^2)/(P)


R=((125\ V)^2)/(7.5\ W)

R = 2083.34 ohms

or

R = 2100 ohms

Hence, the correct option is (d) "2100 ohms"

User Ale
by
8.7k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.