1.

The four arms ABCD of a Wheatstones network have the following resistances: AB = 2 Ω, BC=4 Ω, CD= 4 Ω and DA= 8 Ω. A galvanometer of resistance 10 Ω is connected between B and D. Find the current through the galvanometer, when the potential difference between A and C is 5 V.

Answer»

The current through the galvanometer is 1.071 A.

Explanation:

Given that,

AB = 2 Ω

BC=4Ω

CD = 4 Ω

DA = 8Ω

Galvanometer resistance = 10 Ω

Potential difference between A and C = 5 V

We need to calculate the potential difference

Using KIRCHHOFF's current law at node B

\dfrac{v_{1}-5}{2}+\dfrac{v_{2}-v_{1}}{10}-\dfrac{v_{1}}{4}=0

3v_{1}+2v_{2}=50....(I)

Using Kirchhoff's law at node D

\dfrac{v_{2}-5}{8}+\dfrac{v_{1}-v_{2}}{10}-\dfrac{v_{2}}{4}=0

-9v_{2}+4v_{1}=25.....(II)

From EQUATION (I) and (II)

35v_{2}=125

v_{2}=\dfrac{125}{35}

v_{2}=3.57\ V

Put the VALUE of v₂ in to the equation (I)

3v_{1}+2\times3.57=50

v_{1}=\dfrac{50-2\times3.57}{3}

v_{1}=14.28\ V

We need to calculate the current through the galvanometer

Using formula of ohm's law

I=\dfrac{V_{2}-v_{1}}{10}

Put the value into the formula

I=\dfrac{14.28-3.57}{10}

I=1.071\ A

Hence, The current through the galvanometer is 1.071 A.

Learn more :

Topic : Kirchhoff's law

brainly.in/question/8511522



Discussion

No Comment Found

Related InterviewSolutions