Solving Electromotive Force Homework: 5000V Power Supply & 20kohm Voltmeter

AI Thread Summary
A power supply with an electromotive force (emf) of 5000V shows only 24V when a 20kohm voltmeter is connected, indicating a significant voltage drop. This discrepancy suggests the presence of internal resistance within the power supply, leading to a voltage divider effect. To analyze the situation, it is recommended to draw a circuit diagram to visualize the components and their relationships. Understanding the internal resistance will be crucial for calculating the actual voltage and current in the circuit. The discussion emphasizes the importance of recognizing how load resistance impacts voltage readings in electrical systems.
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Homework Statement



A power supplyused in a lab has an emf of 5000V. However, when a voltmeter of resistance 20kohm is connected to the terminal of the power supply, a reading of only 24V is obtained. Explain this conservation and calculate any necessary quantity.

The Attempt at a Solution



Not really sure where to go with this. I think it has something to do with internal resistance and such but... not really sure. Could someone at least point me in the right direction?

Thank you.
 
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Maybe start by drawing a circuit diagram.

You have a box that nominally has 5000V.

But when you effectively put a 20KΩ load across it, it only reads 25V.

So what you apparently have is some kind of voltage divider.

Perhaps you want to consider some internal resistance?
 
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