Achieving the Balance Point: Current Flow & Galvanometer Reading

In summary, the conversation discusses how when the balance point is achieved, there is no current passing through the galvanometer and it should show 0. The person also shares their working for finding the voltage, but asks for corrections if wrong. The conversation also touches on the problem statement and calculating potential difference using Ohm's Law.
  • #1
werson9339
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Homework Statement


when the balance point is achieved , there're no current passing thru , so Galvanometer should show 0 . Am i right... so there's no current passing thru the 20 ohm resistor . so my working is ( 8.1/120 )(40) = 2.7 V ...
correct me if I'm wrong...

Homework Equations

The Attempt at a Solution


V_xy = V_ac = (9/10) x 10 = 8.1v
k = 8.1/120
V_xy = k (40) = 2.7v

(5/ (5+20+2) ) X E " = 2.7 V

E" = 14.58v[/B]
 

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  • #2
What is the problem statement ?
so there's no current passing thru the 20 ohm resistor
No. It only means there is no current passing through the galvanometer.
 
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  • #3
No current passing through the galvanometer means there is no potential difference over the thing. If we call the point between the 5 ##\Omega## and the 20 ##\Omega## resistors point z: VAC = VXZ.

For VAC you have the right result (but perhaps a typo?) : VAC / VAB = 40/120 and VAB = 9V * 9/10.

And for E' (single quote in the drawing) you also have the right result.
 

What is the balance point in terms of current flow and galvanometer reading?

The balance point refers to the point at which the current flowing through a circuit is equal to the current indicated by the galvanometer. This is when the galvanometer's needle remains at zero, indicating that there is no net flow of current.

Why is it important to achieve the balance point in a circuit?

Achieving the balance point ensures that the circuit is functioning properly and that the current is flowing as intended. It also allows for accurate measurements of the current, which is important in many scientific experiments and applications.

How do you adjust the circuit to achieve the balance point?

To achieve the balance point, you can adjust the resistance in the circuit by using a variable resistor. This allows you to control the amount of current flowing through the circuit until it matches the current indicated by the galvanometer. You may also need to adjust the position of the galvanometer or change the voltage of the power source.

What factors can affect the balance point in a circuit?

The balance point can be affected by changes in the resistance of the circuit, variations in the voltage of the power source, and the presence of other electrical components in the circuit. Temperature changes can also impact the balance point, as resistance can change with temperature.

How does the balance point relate to Ohm's law?

The balance point is directly related to Ohm's law, which states that the current flowing through a circuit is directly proportional to the voltage and inversely proportional to the resistance. When the balance point is achieved, the current and voltage in the circuit are in balance, following the principles of Ohm's law.

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