Question

In an electroscope if aluminum strips are replaced by plastic strips, and a charged object is touched with the metal top of the electroscope.
A) The plastic strips will diverge
B) The plastic strips will not diverge
C) One strips will move away while other will remain same
D) The plastic strips will come more closer

Answer 1

Hint: Aluminum is a metal which is a good conductor of electricity. Aluminum is used in electrical wires because of its low resistance and good conductivity. Aluminum has less weight when compared with copper and it is available at a cheap prize. Aluminum wire will be much thicker but it will be lighter compared to copper and the density of aluminum is one third of copper.

Complete step-by-step solution:
Electroscope is a scientific instrument used to detect the presence of electric charge on a body. Electroscope which detects charge by the movement of a test object due to the coulomb electrostatic force on it. An electroscope requires thousand or hundred volts because an amount of charge on an object is proportional to its voltage.
Electroscope gives only a rough indication of the quantity of charge
In an electroscope if aluminum strips are replaced by plastic strips and a charged object is touched with the metal top of the electroscope. The strips will not spread out or else there will be no charge on aluminum strips and no repulsion of the strips will occur. So we cannot test whether the object is carrying a charge or not
The plastic strips will come more closer

Note: Through metal conductor electric charge can be transferred from a charged object to another. Electroscope which was the first electrical measuring instrument and electrometer measures electric charge quantitatively. Australian scientist Victor Hess used an electroscope in the discovery of cosmic rays.