# Electronics - Series-Parallel Circuits - Discussion

### Discussion :: Series-Parallel Circuits - General Questions (Q.No.9)

9.

What is the total resistance of a circuit when R1 (7 k ) is in series with a parallel combination of R2 (20 k ), R3 (36 k ), and R4 (45 k )?

 [A]. 4 k [B]. 17 k [C]. 41 k [D]. 108 k Explanation:

No answer description available for this question.

 Nandini said: (Oct 30, 2011) Can you explain the answer?

 Nandakishor said: (Jan 12, 2012) Since parallel combination of resisitor is lees than least resistance . therefore parallel combination of 20 36 45 is less than 20. for this combination a series resistance of 7 is added .max answer is less than 20+7=27 there c and d options are not correct . a is also not correct because 7+anything is greater than 7. There fore the correct answer is 17 which is option B.

 Prasanna said: (Aug 19, 2012) RT = R1 + ( 1/R2 + 1/R3 + 1/R4) = 7+(1/20 + 1/36 + 1/45) =7+(10) =17 Kohms

 Revathi said: (Dec 12, 2012) The equivalent resistance for resistors connected in parallel is 1/Re = ((1/R2)+(1/R3)+(1/R4)).

 B Nagendar said: (Feb 26, 2015) In parallel resistors 1/R = (1/R2+1/R3+1/R4).