A 16-Ω resistor is connected in series with another resistor across a 12-V battery. The current in the circuit is 0.42 A. Calculate the value of the unknown resistance.

Answer:unknown resistance=12.6ohms

Explanation:

Known resistance (r) = 16ohms

Unknown resistance (r) = a

Voltage (v) = 12V

Current (I) = 0.42A

Total resistance in series connection is r=16+a

From ohms law v=I x r

12=0.42 x (16 + a)

Divide both sides by 0.42

12 ➗ 0.42 = (0.42x (16+a)) ➗ 0.42

28.6=16+a

a=28.6-16

a=12.6ohms