Basic Electrical Engineering Multiple Choice Questions on “Kirchhoff’s Laws and Network Solutions”.
1. Find the value of I1, I2 and I3.
A. -0.566A, 1.29A, -1.91A
B. -1.29A, -0.566A, 1.91A
C. 1.29A, -0.566A, -1.91A
D. 1.91A, 0.566A, 1.29A
Answer: C
Clarification: Using the matrix method:
Matrix(3,-2,0) (I1)=(5)
(-2,9,-4) (I2)=(0)
(0,-4,9) (I3)=(-15)
Solving this matrix equation, we get I1 = 1.29A, I2 = -0.566A and I3 = -1.91A.
2. Find the value of V, if the value of I3= 0A.
A. 1.739 V
B. 6.5 V
C. 4.5V
D.2.739V
Answer: A
Clarification: 5-3I1+2I2=0, 9I2-2I1=0, -4I2+V=0
On solving,V=1.739V.
3. Find the value of R if the power in the circuit is 1000W.
A. 10 ohm
B. 9 ohm
C. 8 ohm
D. 7 ohm
Answer: C
Clarification: To find the value of I:
VI=P =>100I=1000 => I=10A.
Voltage across the 2 ohm resistor = 20V.
Voltage across the R resistor = 100-20= 80V.
R=V/I => R=80/10 = 8A.
4. Find the current in the 4 ohm resistor.
A. 5A
B. 0A
C. 2.2A
D. 20A
Answer: B
Clarification: The 4 ohm resistor gets shorted since current always prefers the low resistance path. All the current flows to the branch which is connected in parallel to the 4 ohm branch, hence no current flows in the 4 ohm resistance.
5. Nodal analysis is generally used to determine______
A. Voltage
B. Current
C. Resistance
D. Power
Answer: A
Clarification: Nodal analysis uses Kirchhoff’s Current Law to find all the node voltages. Hence it is a method used to determine the voltage.
6. Mesh analysis is generally used to determine_________
A. Voltage
B. Current
C. Resistance
D. Power
Answer: B
Clarification: Mesh analysis uses Kirchhoff’s Voltage Law to find all the mesh currents. Hence it is a method used to determine current.
7. KVL is associated with____________
A. Mesh analysis
B. Nodal analysis
C. Both mesh and nodal
D. Neither mesh nor nodal
Answer: A
Clarification: KVL employs mesh analysis to find the different mesh currents by finding the IR products in each mesh.
8. KCL is associated with_________
A. Mesh analysis
B. Nodal analysis
C. Both mesh and nodal
D. Neither mesh nor nodal
Answer: B
Clarification: KCL employs nodal analysis to find the different node voltages by finding the value if a current in each branch.