Why Does a Galvanometer Show Zero Deflection Despite Potential Differences?

Thus, the potential difference between A and the +ve terminal of the battery would be 0V. Similarly, the potential difference between J and the -ve terminal of the battery would also be 0V. Therefore, no current would flow through the galvanometer and there would be no deflection. In summary, the potential difference between A and J must be equal to the emf of the cell for there to be no current flowing through the galvanometer and for there to be zero deflection. In this scenario, the potential difference between A and the +ve terminal of the battery would be 0V, and the same goes for the potential difference between J and the -ve terminal of the battery. This explains why there
  • #1
abhijit.k939
1
0
Potentiometer conceptual help!

The book that i am using currently states that "If the potential difference between A and J is equal to the emf of the cell, no current flows through the galvanometer. It shows zero deflection."
But suppose A be at 10V and J at 5V, and The +ve terminal of battery at 5V and negative at 0V
Therefore the Potential Difference between AJ and the emf of cell are same ,
but the pottential difference between A and +ve terminal of cell is 5V so current should flow, same for J and -ve terminal.So there should be deflection in galvanometer due to flow of current.Then why not?

Note: A and J are connected to the driving circuit as well as the battery to be measured

I wasnt able to post link for the image directly
http:+//tinypic.com+/r/4kw+7yx/6 (Remove all the + signs)
 
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  • #2


abhijit.k939
It looks from your schematic that node A and the +ve terminal of the battery are the same node. This would prohibit them from being at different voltages.
 

1. What is a potentiometer and how does it work?

A potentiometer, also known as a pot, is an electronic component that is used to measure and adjust the amount of electrical current flowing through a circuit. It consists of a resistive element, a wiper, and three terminals. By adjusting the wiper, the resistance of the potentiometer can be changed, thus altering the current flow in the circuit.

2. What are the different types of potentiometers?

There are three main types of potentiometers: rotary, slide, and trim. Rotary potentiometers have a circular knob that can be turned to adjust the resistance. Slide potentiometers have a slider that moves along a linear track to adjust the resistance. Trim potentiometers are small and used for fine-tuning and calibration purposes.

3. How do I choose the right potentiometer for my circuit?

The key factors to consider when choosing a potentiometer are the resistance range, tolerance, power rating, and physical size. You should also ensure that the potentiometer's resistance value matches the requirements of your circuit. It is recommended to consult the datasheet of the potentiometer or seek guidance from a knowledgeable electronics supplier.

4. Can I use a potentiometer to control the brightness of an LED?

Yes, you can use a potentiometer to control the brightness of an LED. By connecting the LED in series with the potentiometer, you can adjust the resistance to control the current flowing through the LED, thus changing its brightness. This is a common application of potentiometers in electronic circuits.

5. Are there any common issues or troubleshooting tips for potentiometers?

One common issue with potentiometers is that they can wear out over time, resulting in a change in their resistance values. To troubleshoot this, you can check the resistance of the potentiometer using a multimeter and replace it if necessary. Another issue is that the wiper of the potentiometer can become dirty or lose contact, which can lead to erratic readings. Cleaning the wiper with a small amount of contact cleaner can usually solve this problem.

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