Power supply shows 24V instead of 5000V when voltmeter connected

[caltzx]

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.

 

[LowlyPion]

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?