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Part ai): Indicate the direction of flow of electons. Electrons are negative charges. They will flow towards the terminal with a positive potential.
Part aii) Draw the charges on the sphere. As electrons have flown to the positive terminal, the sphere has more positive charges than negative charges. So, the sphere is positively charged. The charges are spread out evenly.
Draw the charges on the theads. Since the ball is positively charged, the ends of the threads nearer to the ball will be induced to be negativedly charged. The far end of the thread from the ball will have the opposite charge, ie positive charge.
From the drooping position to standing up position, the threads have to defy gravitational force. This shows that there is a force acting on the threads in the outward direction from the centre of the ball. As electric field is defined as a region where a small positive charge experience an electric force, this shows that there is an electric field around the ball.