(a) Three resistors `3Omega, 4Omega, and 12Omega` are connected in parallel. What is the effective resistance of the combination?
(b) If the combination is connected to a battery of emf 6V and internal resistance `0.5Omega`, find the current drawn from the battery and terminal potential difference across the battery.

Explanation

(a)Effctive resistance `R_(p)` is given by
`(1)/(R_(p))=(1)/(R_(1))+(1)+(1)/(R_(2))+(1)/(R_(3))`
Substituting ,`(1)/(R_(p))=(1)/(3)+(1)/(4)+(1)/(12)`
`(1)/(R_(p))=(4+3+1)/(12)=(8)/(12)=(2)/(3)`
Effective resistance of the combination :
`R_(p)=3//2Omega=1.5Omega`
(b)Current drawn from the battery is ,
`I=(epsi)/(R_(p)+r)`
`I=(6)/(1.5+0.5)=3A`
Terminal potential difference:
V=`epsi`-Ir=6-3 (0.5)=4.5 V
OR teminal potential difference :
`V=IR_(P)=3(1.5)=4.5V`