Advertisements
Advertisements
Question
Using Kirchhoff’s rules determine the value of unknown resistance R in the circuit so that no current flows through 4 Ω resistance. Also find the potential difference between A and D.
Advertisements
Solution
Apply Kirchhoff’s In loop ABCFA:-
I + I + 4I1 = 9 − 6
2I + 4I1 = 3 … (1)
As there is no current flowing through the 4Ω resistance,
I1 = 0
Or, 2I = 3
Or, I = 1.5A
Thus the current through resistances R is 1.5A.
As there is no current through branch CF, thus equivalent circuit will be,
By applying Kirchhoff’s loop law we get,
1.5 + 1.5 + R (1.5) = 9 − 3
R = 2Ω
Potential difference between A and D = (9 − 3) = 6V
APPEARS IN
RELATED QUESTIONS
Determine the current drawn from a 12 V supply with internal resistance 0.5 Ω by the infinite network shown in the figure. Each resistor has 1 Ω resistance.
Given the resistances of 1 Ω, 2 Ω, 3 Ω, how will be combine them to get an equivalent resistance of 6 Ω?
Calculate the value of the resistance R in the circuit shown in the figure so that the current in the circuit is 0.2 A. What would b the potential difference between points B and E?
Calculate the value of the resistance R in the circuit shown in the figure so that the current in the circuit is 0.2 A. What would b the potential difference between points A and B?
On which conservation principle is Kirchoff's Second Law of electrical networks based?
Twelve wires each having a resistance of 3 Ω are connected to form a cubical network. A battery of 10 V and negligible internal resistance is connected across the diagonally opposite corners of this network. Determine its equivalent resistance and the current along each edge of the cube.
State the principle of potentiometer.
Two cell of 1.25 V and 0.75 V are connected parallel. The effective voltage will be:-
Three resistors having resistances r1, r2 and r3 are connected as shown in the given circuit. The ratio `i_3/i_1` of currents in terms of resistances used in the circuit is:
In a meter bridge the point D is a neutral point (Figure).
- The meter bridge can have no other neutral point for this set of resistances.
- When the jockey contacts a point on meter wire left of D, current flows to B from the wire.
- When the jockey contacts a point on the meter wire to the right of D, current flows from B to the wire through galvanometer.
- When R is increased, the neutral point shifts to left.
Derive the equation of the balanced state in a Wheatstone bridge using Kirchhoff’s laws.
The figure below shows two batteries, E1 and E2, having emfs of 18V and 10V and internal resistances of 1 Ω and 2 Ω, respectively. W1, W2 and W3 are uniform metallic wires AC, FD and BE having resistances of 8 Ω, 6 Ω and 10 Ω respectively. B and E are midpoints of the wires W1 and W2. Using Kirchhoff's laws of electrical circuits, calculate the current flowing in the wire W3:
What is Kirchhoff's Current Law also called?
At any junction, what does Kirchhoff's Current Law state?
After a charge completes one full loop and returns to its starting point, what is the net change in potential?
Which sign convention is usually used for current entering a junction?
What is the sign of the emf when moving from the negative terminal to the positive terminal of a cell?
How are Kirchhoff's laws used in analysing a general network with several unknown branch currents?
