21. If € = 8.0 V, at what rate is the emf providing energy to the circuit shown? 15 2
10 22
12 V
+
1022.
a. 8.4 W
b. 7.6 W
C.5.6 W
d. 11 W
e. 2.0 W

  c.  5.6 W

Explanation:

We can write the Kirchoff's voltage law (KVL) equations for the circuit using i1 for the clockwise current in the left loop, and i2 for the clockwise current in the right loop. Then the circuit equations are ...

  i1 (10 +10) -i2(10) = 12

  -i1(10) +i2(10 +15) = 8

Using Cramer's rule to find i2, we have ...

  i2 = (12(-10) -8(20))/((-10)(-10) -(25)(20)) = -280/-400 = 0.7

The power supplied by the Emf is ...

  (8 V)(0.7 A) = 5.6 W . . . . . matches choice C

there was no answer choices but i think its representative