Question

A 9.0 volt battery is connected to four resistors in a parallel circuit. The resistors have 7.0 Ω, 5.0 Ω, 4.0 Ω, and 2.0 Ω respectively. What is the total current in the circuit?

Answer 1

parallel resistance =
`(1)/(7)` +
`(1)/(5)` +
`(1)/(4)` +
`(1)/(2)`
=
`(140)/(153)`

now , V= 9V
V = IR
I =
`(V)/(R)`
I =
`(9)/(140)` x 153
I = 9.835714 A

Answer 2

series,effective resistance =R₁+R₂+R₃...
parallel,effective resistance 1/R=1/R₁ +1/R₂ +1/R₃...

Here,effective resistance 1/R =1/7 +1/5+ 1/4+1/2
=1.092
R = 1/1.092 =0.915Ω
voltage V=9 V
current I=V/R
I=9 / 0.915
=9.83 A