Figure 1 shows a network of resistors connected to a voltage source. As shown in the figure, the
network consists of 2 meshes and the values of all the resistors are given. In this question mesh
current analysis is used to find the currents in all the resistors.
(a) Use KVL to write two equations in terms of the two mesh currents, I1 and I2. Do not solve
them in this part. Note only the resistor R3 is shared by both meshes. (5)
(b) Use the two equations derived in part (a) to solve for the mesh currents, I1 and I2. (5)
(c) Find the currents in all five resistors by calculating the branch currents from the mesh
currents. (5)
(d) Calculate the power dissipated in all five resistors and the power delivered by the source.
Show that power is conserved. (5)
(e) Find the Thevenin equivalent circuit (find Vt and Rt) between the two terminals V1 and
ground as shown in Figure 2. Hint – Find the open‐circuit voltage between V1 and ground and
the short circuit current from V1 to ground. (5)
(f) If the value of R3 is varied while all the other components are the same as before, find the
value of R3 which will maximize the power delivered to R3. What is the maximum power
delivered to R3. (5)
Figure 1 shows a network of resistors connected to a voltage source. As shown in the figure, the
network consists of 2 meshes and the values of all the resistors are given. In this question mesh
current analysis is used to find the currents in all the resistors.
(a) Use KVL to write two equations in terms of the two mesh currents, I1 and I2. Do not solve
them in this part. Note only the resistor R3 is shared by both meshes. (5)
(b) Use the two equations derived in part (a) to solve for the mesh currents, I1 and I2. (5)
(c) Find the currents in all five resistors by calculating the branch currents from the mesh
currents. (5)
(d) Calculate the power dissipated in all five resistors and the power delivered by the source.
Show that power is conserved. (5)
(e) Find the Thevenin equivalent circuit (find Vt and Rt) between the two terminals V1 and
ground as shown in Figure 2. Hint – Find the open‐circuit voltage between V1 and ground and
the short circuit current from V1 to ground. (5)
(f) If the value of R3 is varied while all the other components are the same as before, find the
value of R3 which will maximize the power delivered to R3. What is the maximum power
delivered to R3. (5)
