### Tut 1 Coulomb

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**1.** What is the charge on 1 electron, and what is the charge of 1 proton?

**2.** Calculate the number of electrons responsible for a charge of -4 x 10^{-14}C.

**3.** Object A has a charge of -8nC and object B has a charge of 4nC.

**3.1.** Will A and B attract or repel each other? Why?

**3.2.** A and B are brought into contact with each other. Calculate the new charges of A and B.

**3.3.** Will A and B attract or repel each other? Why

**3.4.** In which direction will charge be transferred, from A to B or from B to A?

**3.5.** Calculate the amount of charge transferred.

**3.6.** Calculate the number of electrons transferred.

**4.** The charge of sphere X is 8nC. When it was brought into contact with sphere Y, the charge of X became 5nC.
Calculate the original charge of Y.

**5.** Two objects A and B carry charges of -8nC and 2nC. They are placed a distance of 0,02m apart.

Calculate the magnitude of the electrostatic force between them.

**6.** The magnitude of the electrostatic force between charges X and Y placed 24mm apart is 3 x 10^{-5}N. The charge on X is 6μC.
Calculate the magnitude of the charge on Y.

**7.** How far apart should two charges each of magnitude 5nC be placed so that the electrostatic force between them becomes 4 x 10^{-7}N?

**8.** Two identical point charges repel each other with a force of 0,25 x 10^{-3} N. If the distance between them is 50mm calculate the charge of each.

**9.** As two oppositely charged objects gradually and continuously approach each other, what effect would this have on the magnitude of electrostatic force between them? Show by means of a graph.

**10.** What is the charge of a magnesium ion in coulombs?