Question
Fig. 10.1 shows the apparatus for an experiment on electrostatics.
(a) Identify the pieces of equipment that are electrical conductors and those that are electrical insulators. Draw a line from each piece of equipment to the correct box.
(b) State and explain how the polythene strip can be given a negative charge.
(c) Describe how the apparatus in Fig. 10.1 could be used to demonstrate that the polythene strip has a negative charge.
Answer/Explanation
Answer:
(a) clamp AND nail to conductor
AND stirrup AND thread to insulator
(b) rubbed with a cloth
electrons transfer to polythene / from cloth
(c) (bring) a negatively charged rod / strip / object near
repulsion
Question
(a)A student rubs a polythene rod with a dry cloth. The polythene rod becomes negatively charged.
Describe and explain how the rod becomes negatively charged.
(b) The negatively charged polythene rod hangs from a nylon thread so that it is free to turn
The student charges a second polythene rod and brings it close to the first rod, as shown in Fig. 11.1.
Describe and explain what happens when the negatively charged rods are close to each other.
Answer/Explanation
Answer:
(a) friction (between cloth and rod)
(causes) electrons to move
from cloth / to rod
(b) rod {moves or rotates} away
like charges repel