Three equal resistors of 30 OHM resistance are together in parallel with a 12 V battery attached. The equivalent resistance of this circuit is?

Question

A) 10 OHM, with the current being 1.2 A

B) 20 OHM, with the current being 0.6 A

C) 30 OHM, with the current being 0.4 A

D) 40 OHM, with the current being 0.3 A

E) 60 OHM, with the current being 0.2 A

Answer 1

Parallel resistors add like this:

1/R_equiv = 1/R1 + 1/R2 + 1/R3

1/R_equiv = 1/30 + 1/30 + 1/30

1/R_equiv = 3/30 = 1/10

R_equiv = 10 Ω

By Ohm's Law, voltage = current times resistance (V = IR) so I = V/R = 12/10 = 1.2 amps