1. Kirchhoffs junction law follows from conservation of charge.
2. Kirchhoffs loop law follows the conservative nature of the electric field.
Both 1 and 2 are correct
2 is correct but 1 is wrong
1 is correct but 2 are wrong
Both 1 and 2 are wrong
Answer.2
Kirchhoff’s junction law states that the current entering the junction is equal to the current leaving the junction, which indirectly means the charge entering the junction is equal charge leaving the junction. From the statement, it is clear that Kirchhoff’s junction law follows the conservation of charge. Therefore statement 1 is correct.
Kirchhoff’s loop law states that the net potential drop in a loop is Zero Σ V = 0, which means potential changes around a closed loop is zero.
Voltage is the measure of energy per unit charge in this context KVL can be restated as the total energy gained per unit charge must be equal to the amount of energy lost per unit charge (ie: the Law of conservation of Energy). Therefore statement 2 is correct.
32. Find the value of the current I by using KCL?
A. 8A
B. 7A
C. 6A
D. 5A
Answer: A
KCL states that the amount of charge entering a junction is equal to the amount of charge leaving it, hence it is the conservation of charge.
At the junction, I-2+3-4-5 = 0.
Hence I = 8A.
33. If two capacitors having a capacitance of 5 μF and 10 μF respectively are connected in series across a 200 V supply, find the potential difference across each capacitor.
50 V, 100 V
133.33 V, 66.66 V
200 V, 100 V
100 V, 200 V
Answer.2. 133.33 V, 66.66 V
Given,
C1 = 5 μF
C2 = 10 μF
V = 200 V
From the above concept, the voltage across C1 is given as,
VC1 = V × C2/(C1 + C2)
= 200 × 10 (10 +15) = 133.33 V
And the voltage across C2 is given as,
VC2 = V × C1/(C1 + C2)
= 200 × 5 (10 +15) = 66.66 V
34. Kirchhoff’s Current law is based on the law of conservation of _________
A. energy
B. momentum
C. mass
D. charge
Answer: D
Kirchhoff’s current law is based on the law of conservation of charge i.e, charge that flows in = charge that flows out.
35. The figure shown here is a branch of an electric current where the current is moving from A to B. Find the value of (VA – VB).
5 V
30 V
20 V
10 V
Answer.4. 10 V
By applying the KVL,
-VA + 2(5) + 10 – 16 + 2(3) + VB = 0
⇒ VA – VB = 10 V
36. The current law represents a mathematical statement of fact that ________
A. voltage cannot accumulate at node
B. charge cannot accumulate at node
C. charge at the node is infinite
D. none of the mentioned
Answer: B
Kirchhoff’s current law is based on the law of conservation of charge i.e, charge that flows in = charge that flows out. The charge cannot accumulate at the node, it can only flow in and out of the node.
37. In the circuit shown below, the voltage and current sources are ideal. The voltage Vout across the current source, in volts, is
0
5
10
20
Answer.4. 20
Apply KVL in the loop as shown below,
The current flow through 2 Ω is 5 A as shown in fig and it will give a drop of 10 V.
– Vout + 10 + 10 = 0
Vout = 20 V
38. Kirchhoff’s current law is applied at ___________
A. loops
B. nodes
C. both loop and node
D. none of the mentioned
Answer: B
Kirchhoff’s current law is based on the law of conservation of charge i.e, charge that flows in = charge that flows out.
Kirchhoff’s current law can be applicable to nodes only.
39. In the circuit shown below, what will be the power absorbed by the dependent source (voltage source)?
