Question

Three resistances R1, R2 and are connected in parallel, show that their equitvalent resistance is 1/R = 1/R1 + 1/R2 + 1/R3​

Answer 1

Answer:

Explanation:

As in parallel combination, the potential through all resistors are same but current is the individual sum of all

Hence,

I=I1 + I2 +I3

Since v=IR

Or I=V/R

Therefore

V/R= V/R1 + V/R2 +V/R3

By taking V as common

We get

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

Showed !

Answer 2

Answer:

here ,

R1 = 1 BULB , R2 = 10CUBE BULB and R3 = 10 6 BULB

SO, 1/ R = 1/1 + 1/10 cube + 1/10 6

=10 6 + 10 3 + 1/ 10 6

= 1001001/10000000

= R = 10000000/10000000

= 0.999 bulb

= 1 bulb