Download Find the current through the 3* resistor if the entire combination is

11
Find the current through the 3Ω resistor if the entire
combination is connected across a 24V source of emf.
5Ω
4Ω
5Ω
3Ω
24V
6Ω
9Ω
9.94 V
6Ω
8Ω
9.94 V 9Ω
9Ω
24V
6Ω
2.34 A
9.94 V
9Ω
24V
10.24
2.34 A
2. Identify the unknown: I3=?
3. Work backwards using what
you know about series / parallel
9Ω
24V
1. First simplify the circuit
4.24
Ω
• I3=I5 Current is same in series
• I3= I8 b/c they are equivalent
• V4.24= V8= V9 b/c they are parallel
• I6= I10.24 Current is same in series
4. Get crackin’ find I10.24 first
I10.24 = VT/R10.24 = 24/10.24 = 2.34 A
5. To find V8 you’ll need to find V4.24
V4.24 = I4.24R4.24 = (2.34 A)(4.24) =9.94V
11
Find the current through the 3Ω resistor if the entire
combination is connected across a 24V source of emf.
5Ω
4Ω
5Ω
3Ω
24V
6Ω
• V4.24= V8= V9 b/c they are parallel
9Ω
• I6= I10.24 Current is same in series
8Ω
24V
6Ω 2.34 A
9Ω
7. Realize that I8= I3
Feel victorious!
9Ω
6Ω
6. Now find I8
I8 = V8/R8 = 9.94/8 = 1.24 A
9.94 V
2.34 A
9.94 V
9Ω
24V
• I3=I5 Current is same in series
• I3= I8 b/c they are equivalent
9Ω
24V
Work backwards using what you
know about series / parallel
10.24
2.34 A
4.24
Ω
I3 = 1.24 A