Question

You have two electric lamps having rating 40 W, 220 V and 60 W, 220 V. Which of the two has a
higher resistance? Give reason for your answer. If these two lamps are connected to a source of 220 V,
which will glow brighter?You have two electric lamps having rating 40 W, 220 V and 60 W, 220 V. Which of the two has a

higher resistance? Give reason for your answer. If these two lamps are connected to a source of 220 V,

which will glow brighter?

Answer 1

Answer:

Explanation:

According to the definition Power is direct proportion to the voltage and inversely proportion to the  resistance therefore when the power increases the voltage also increases thereby creating an decrease in resistance .

p = v²/R

making R subject of the formula we get R =  V²/P

R = Resistance =?

V = Voltage = 220V, 220V

P = Power = 40W, 60W

Therefore

R1 = 220²/ 4O = 1210

R2 = 220²/ 60 = 806.7

How we can conclude that 40W, 220V will have a higher resistance as compared to 60W, 220V

↔Reason being power is inversely proportion to the resistance .

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