Question

Resistance of a 110v, 40w lamp will be​

Answer 1

Answer:

302.5 ohms

Explanation:

Given :

• Voltage or the potential difference = v = 110 volts

• Power rating = 40 watts

To find :

• Resistance of the following setup with potential difference of 110 volts and power rating of 40 watts

Power = voltage²/resistance

40=110²/R

40R=12,100

R=12100/40

R=302.5 ohms

The resistance of the following circuit with voltage 110 volts and power 40 watts is 302.5 ohms

Answer 2

Given ,

Voltage , V = 110 v

Power , P = 40 w

Resistance , R = ? Ω

We know that " Power is defined as the product of voltage and current "

⇒ P = VI ... (1)

From Ohm's law , V= IR

⇒ I = V/R

Sub. I = V/R in (1) , we get ,

⇒ P = V² / R

⇒ 40 = 110² / R

⇒ R = 110² / 40

⇒ R = 302.5 Ω

So , Resistance of a 110 v , 40 w lamp is 302.5 Ω