Question

a battery of 12 v is connected to a series combination of resistors 3,4,5 and 12 ohm how much current would flow through the 12 ohm resistor

Answer 1

Total resistance = Rs = ?
Rs = 3 ohm + 4 ohm + 5 ohm + 12 ohm
Rs = 24 ohm

Potential difference = v = 12 v
Total resistance = Rs = 24 ohm
Current = I = ?

V = IR
V/R = I
12v/24 ohm = I
0.5 A = I

when resistors are connected in series then same amount of current flow through the each resistor

so 0.5 ampere current flow through 12 ohm resistor