Question

If 5 ohms 10 ohms 15 ohms resistors are connected in parallel . what is the effective resistence

Answer 1

Answer:

2.72727273 ohms

Explanation:

1/5+1/10+1/15

do the LCM

which comes out to be 30

6+3+2/30=11/30

then do it becomes 30/11

which is 2.72727273

Answer 2

Answer:

2.5 ohms.

Explanation:

The effective resistance of multiple resistors while connected in parallel can be obtained hy:

1/R = 1/R1 +/ 1/R2 +1/R3 +....

Where,

'R' is the effective resistance.

'R1' is resistance of first resistor.

'R2' is resistance of second resistor.

'R3' is resistance of third resistor and so on.

Now as we are given:

R1 = 5ohms, R2 = 10ohms and R3 = 15ohms; thus,

1/R = 1/R1 + 1/R2 + 1/R3

1/R = 1/5 + 1/10 + 1/15

Now, taking the l.c.m.;

1/R = (3+2+1)/15

1/R = 6/15

And lastly, reciprocating the equation;

R = 15/6

R = 2.5ohms