Introduction to Electrical Systems EE 111

Assignment 1

Q1. Consider the circuit shown in Figure 1. Perform nodal analysis and hence determine VA, VB, VC. Also determine the power delivered by the current source.

+_

+_ +_

40 V20 V

440 V

25 A

0.2 S

0.15 S

0.05 S 0.25 S

VAVBVC

Figure 1

Q2. In the circuit shown in Figure 2, Vs1= -10 V, Is2 = 1 A, and all resistors are 10 . Apply nodal analysis to determine VA, VB, VC.

+_ Vs1 Is2

+

_

vx

+ _3 vx

cVVBVA

Figure 2

Q3. Consider the circuit shown in Figure 3 along with the defined loops 1, 2 and 3. Determine I1, I2, I3 and hence determine, v.

+_

+_14 V 6 V

1

4 2

2

1

1

I1

I2

I3

Figure 3

Q4. Consider the circuit shown in Figure 4, wherein Vs1 = 250 V and Is2 = 0.75 A. Write two mesh equations and hence determine VB.

+_ Vs1

_

x

+

I

100 300 Ix

200 200

200Is2

+

_VB

Figure 4

Q5. Consider the linear network of Figure 5. Two separate dc measurements are taken. In the first experiment it is found that when Va = 7 V and Ib = 3 A, the load current is Iload = 3 A. In the second experiment it found that when Va = 7 V and Ib = 1 A, then Iload = 3 A. Compute Iload when Va = 15 V and Ib = 9 A.

+_ R

I load

Va

Ib

LinearNetwork

containingdependent

sources

Figure 5

Q6. Find the Thevenin equivalent circuit of the network shown in Figure 6 as viewed from A - B

+

_

A

B

72 V

54 mA

8 k

4 k

6 k

2 k

4 k

Figure 6

Q7. Find Thevenin equivalent of the circuit shown in Figure 7 as viewed from A B. What is the Nortons equivalent?

B

A+

_

vx

Ix

- 2Ix

0.01vx

100

800

300 100

Figure 7

Q8. Find the Norton and Thevenin equivalent of the circuit shown in Figure 8.

103.0 A

+ _i

4i

1

1 6

Figure 8

Q9. For the circuit shown in Figure 9, find the load resistance, RL needed for maximum power transfer. Also determine the maximum power delivered to the load resistor, RL.

+

_

400

200

1 k

ohm

RL

0.00

15 V

L

VL0.1 A

Figure 9