A gold leaf electroscope with a zinc plate top is charged by briefly connecting it to the negative electrode of a high-voltage supply. Explain how the gold leaf will appear and how the leaf can be caused to drop again.

The gold leaf will diverge from the metal stem. This is because connecting the negative electrode to the zinc plate, causes an influx of electrons to flow into the electroscope. When the electrode is removed, the electroscope is left with an overall negative charge. This causes the part of the electroscope that can move, the gold leaf, to repel from the rest and diverge.To return it, photons with energy above the work function of the zinc is needed to trigger the electrons from the plate to be emitted. For zinc, this corresponds to UV photons or any with a shorter wavelength, even at a low intensity.

RN
Answered by Rebecca N. Physics tutor

4460 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

A car of mass m travelling with a velocity v comes to rest over a distance d in time t. The constant frictional force acting on the car while it is braking is found using:


How does conservation of momentum work when at least one of the bodies in the problem changes mass?


Explain what is meant by specific latent heat of fusion


How does the angle of an inclined plane relate to its efficiency, given the coefficient of friction between a body and the plane?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences