When the ruler is broughı near the inetal knob, it repels electrons in the metal. Electrons move away froni the ruler and down the metal rod. The knob now has a positive charge. The thin pieces of metal foil at the bottom of the metal rod now have a negative charge.
Answer:
2
Explanation:
A rigid body is not elastic.
i.e. it does not change shape.
This is known as overextension! (the correct answer is B.)
the above three pictures may help you
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