21. Three lamps of 750, 100 Q and 250 m, are connected in parallel. What is...

Question

Question

21. Three lamps of 750, 100 Q and 250 m, are connected in parallel. What is the total resistance? a. 425 Q b. 1410 C. 372 d..

Answer 1

Answer #1

Multiple questions posted,so answering only the first question:

21. When n resistances R1, R2...Rn are connected in parallel,1/R=1/R1+1/R2+....1/Rn.

So,when 3 resistances, 75 ohm, 100 ohm, 250 ohm are in parallel, 1/R=1/75+1/100+1/250,where R is equivalent resistance.

=>1/R=0.027333

=> R=37 ohms approximately(option C)

Answer 2

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