Question

The most common type of electroscope is
(A) Gold leaf electroscope
(B) Elongated electroscope
(C) Swipe electroscope
(D) None

Answer 1

Hint: An electroscope consists of a vertical metal rod that sticks out of a glass enclosure; a piece of plastic​ ​prevents electric charge from going from the metal rod and metal leaves at the bottom on to the cylindrical enclosure, which is usually metal as well.

Complete answer:
 Gold leaf electroscope- A metal disc is connected to a narrow metal plate and a thin piece of gold leaf is fixed to the plate. The whole of this part of the electroscope is insulated from the body of the instrument by contact - a charged rod is touched on the surface of the disc and some of the charge is transferred to the electroscope. The electroscope is an instrument for checking a body whether it is electrically charged or not and also used for finding the nature of charge. The gold leaf electroscope is one of the most popular electroscopes. A gold leaf electroscope is the device used to detect electrical charge and, if compared to a known charge, can also detect its polarity. It shows the presence and magnitude of a charge by applying a charge to a top plate of copper connected to two pieces of gold leaf through a stem.

So, the most common type of electroscope is gold leaf electroscope.

Note: An electroscope is a scientific instrument that is used to detect the presence and magnitude of electric charge on a body. There are three classical types of electroscopes: pith-ball electroscope (first), gold-leaf electroscope (second), and needle electroscope (third).