Advertisements
Advertisements
Question
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.


Advertisements
Solution

(a)
Applying KVL in the above loop, we get:-
\[10i + 6 + 5i + 12 = 0\]
\[ \Rightarrow 10i + 5i = - 18\]
\[ \Rightarrow 15i = - 18\]
\[ \Rightarrow i = - \frac{18}{15} = - \frac{6}{5} = - 1 . 2 A\]
The negative sign indicates that current is flowing in the direction opposite to our assumed direction.
(b) Potential drop across the 5 Ω resistor= 5i = 5×(-1.2 ) = -6 V
(c) Potential drop across the 10 Ω resistor = 10i = (-1.2) × 10 = 12 V

(d)
Applying KVL in the above loop, we get:-
\[10i + 5i + 6 + 12 = 0\]
\[ \Rightarrow 15i = - 18\]
\[ \Rightarrow i = - 1 . 2 A\]
Potential drop across the 5Ω register = -6 V
Potential drop across the 10Ω register = -12 V
APPEARS IN
RELATED QUESTIONS
Given n resistors each of resistance R, how will you combine them to get the (i) maximum (ii) minimum effective resistance? What is the ratio of the maximum to minimum resistance?
State Kirchhoff's rules and explain on what basis they are justified.
Given the resistances of 1 Ω, 2 Ω, 3 Ω, how will be combine them to get an equivalent resistance of (11/5) Ω?
State Kirchhoff's rules for an electric network. Using Kirchhoff's rules, obtain the balance condition in terms of the resistances of four arms of Wheatstone bridge.
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.

Consider the following two statements:-
(A) Kirchhoff's junction law follows from conservation of charge.
(B) Kirchhoff's loop law follows from conservative nature of electric field.
Find the circuit in the three resistors shown in 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.

Two unequal resistances, R1 and R2, are connected across two identical batteries of emf ε and internal resistance r (see the figure). Can the thermal energies developed in R1 and R2 be equal in a given time? If yes, what will be the condition?

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 Kirchhoff’s current rule.
State and explain Kirchhoff’s rules.
In a potentiometer arrangement, a cell of emf 1.25 V gives a balance point at 35 cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 63 cm, what is the emf of the second cell?
The instrument for the accurate measurement of the e.m.f of a cell is ______.
Kirchhoff’s second law is a consequence of law of conservation of ______.
Assertion: Kirchhoff’s junction rule follows from conservation of charge.
Reason: Kirchhoff’s loop rule follows from conservation of momentum.
The Kirchhoff's second law (ΣiR = ΣE), where the symbols have their usual meanings, is based on ______.
Kirchhoff’s junction rule is a reflection of ______.
- conservation of current density vector.
- conservation of charge.
- the fact that the momentum with which a charged particle approaches a junction is unchanged (as a vector) as the charged particle leaves the junction.
- the fact that there is no accumulation of charges at a junction.
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.
The circuit in figure shows two cells connected in opposition to each other. Cell E1 is of emf 6V and internal resistance 2Ω; the cell E2 is of emf 4V and internal resistance 8Ω. Find the potential difference between the points A and B.
Two cells of voltage 10V and 2V and internal resistances 10Ω and 5Ω respectively, are connected in parallel with the positive end of 10V battery connected to negative pole of 2V battery (Figure). Find the effective voltage and effective resistance of the combination.

State the two Kirchhoff’s rules used in the analysis of electric circuits and explain them.
The value of current in the 6Ω resistance is ______.
At any junction, what does Kirchhoff's Current Law state?
What is Kirchhoff's Voltage Law also called?
What is a junction or node?
What is a loop?
Which term is defined as the rate of flow of charge through a conductor?
What is emf?
If currents \[I_1\] and \[I_2\] enter a junction and currents \[I_3\] and \[I_4\] leave it, which equation follows from Kirchhoff's First Law?
Which algebraic form is equivalent to \[I_1+I_2=I_3+I_4\]?
In a closed loop containing cells and resistors, what equals the total potential drop across the resistors?
Which sign convention is usually used for current entering a junction?
Which sign convention is usually used for current leaving a junction?
While moving opposite to the direction of current through a resistor, how is the potential change treated?
How are Kirchhoff's laws used in analysing a general network with several unknown branch currents?
