An electroscope is a sensitive instrument used to detect, measure, and identify electric charges. It consists of a brass rod with a disk at the top and gold leaf strips at the bottom, enclosed in a glass jar for insulation. Charges move freely between the disk and leaves through the rod. When a charged object is brought near or in contact with the disk, the leaves diverge due to the repulsion of like charges. The electroscope can be charged by induction or conduction and is also used to determine the type of charge, identify conductors and insulators, and detect the presence of charge.
What is an electroscope?
An electroscope is a sensitive instrument used to detect, measure, and identify electric charges.
What are the main components of a gold leaf electroscope?
A gold leaf electroscope consists of a brass rod, a brass disk at the top, two gold leaf strips at the bottom, a glass jar for insulation, and an aluminum foil grounded with a copper wire.
How does an electroscope detect the presence of charge?
When a charged object is brought near the disk, charges are induced in the electroscope. This causes the leaves to diverge as they acquire similar charges and repel each other.
What is the purpose of the aluminum foil in an electroscope?
The aluminum foil, usually grounded, protects the gold leaves from external electrical disturbances.
How can an electroscope be charged by electrostatic induction?
A charged body is brought near the disk, causing opposite charges to gather on the disk and like charges to move to the leaves. The leaves’ charges are then grounded, leaving the electroscope with a net charge when the ground connection is removed.
When charging an electroscope by induction, what happens after the Earth connection is broken?
a) The electroscope becomes neutral
b) The electroscope retains a net positive charge
c) The electroscope retains a net negative charge
d) The electroscope is fully discharged
Answer: b) The electroscope retains a net positive charge
What is the purpose of the grounded aluminum foil in an electroscope?
a) To increase the charge on the electroscope
b) To protect the gold leaves from external disturbances
c) To measure the charge on the electroscope
d) To prevent the leaves from diverging
Answer: b) To protect the gold leaves from external disturbances
What does it indicate when the gold leaves of an electroscope collapse?
a) The body is positively charged
b) The body is negatively charged
c) The body is neutral
d) The body is a good conductor
Answer: d) The body is a good conductor
How can an electroscope be used to detect the type of charge on a body?
a) By measuring the voltage
b) By observing the change in the divergence of leaves
c) By observing the movement of the disk
d) By measuring the resistance
Answer: b) By observing the change in the divergence of leaves
What occurs when a negatively charged rod is brought in contact with the disk of a neutral electroscope?
a) The leaves collapse
b) The leaves diverge
c) The electroscope is uncharged
d) The electroscope is grounded
Answer: b) The leaves diverge