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
Use Kirchhoff's rules to obtain conditions for the balance condition in a Wheatstone bridge.
ε1 and ε2 are two batteries having emf of 34V and 10V respectively and internal resistance of 1Ω and 2Ω respectively. They are connected as shown in the figure below. Using Kirchhoff’s Laws of electrical networks, calculate the currents I1 and I2.
State Kirchhoff's rules and explain on what basis they are justified.
Determine the equivalent resistance of networks shown in Fig.
In the given circuit, assuming point A to be at zero potential, use Kirchhoff’s rules to determine the potential at point B.
Consider the circuit shown in the figure. Find (a) the current in the circuit (b) the potential drop across the 5 Ω resistor (c) the potential drop across the 10 Ω resistor (d) Answer the parts (a), (b) and (c) with reference to the figure.
Twelve wires, each of equal resistance r, are joined to form a cube, as shown in the figure. Find the equivalent resistance between the diagonally-opposite points a and f.
Lightning is a very good example of a natural current. In typical lightning, there is 109 J energy transfer across the potential difference of 5 × 107 V during a time interval of 0.2 s. Using this information, estimate the following quantities:
- the total amount of charge transferred between cloud and ground
- the current in the lightning bolt
- the power delivered in 0.2 s.
The Kirchhoff's second law (ΣiR = ΣE), where the symbols have their usual meanings, is based on ______.
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 :
