Q3. In the given circuit:
• R? = 6.00 ?
• R? = 4.00 ?
• R? = 30.0 ?
• R? = 15.0 ?
Use the current directions suggested on the
diagram in your solution.
(a) Find $I_1$, the reading of the ammeter, and the unknown battery $\mathcal{E}_1$ if the switch is open.
• $\mathcal{E}_2$ = 15.0 V
• $\mathcal{E}_3$ = 10.0 V
• r = 1.00 ?
• $I_2$ = 2.00 A