Question

HELP NEEDED FAST (last cram sessions before finals)

Answer 1

Explanation:

The sum of the voltages of the components connected in a series circuit is equal to the voltage across the battery.

$V_T = V_1 + V_2 +V_3$

From Ohm's law ($V=IR$) and in a series circuit, the amount of current flowing through the components is the same for all. So we can write $V_T$ as

$V_T= 75\:\text{V} = I(170)+I(190) + 21\:\text{V}$

$I(170+190)=54\:\text{V}$

$I= \dfrac{54\:\text{V}}{360\:\text{ohms}}=0.15\:\text{A}$