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The diagram below shows two small identical spheres, P and Q, on insulated stands. The charge on sphere P is -3 × 10-6 C and the charge on sphere Q is unknown.
10.1 Calculate the number of electrons in excess on sphere P. (3)
The two spheres are brought into contact and are then returned to their original positions. Each sphere now carries a charge of -1 × 10-6 C.
10.2 Calculate the original charge on sphere Q before the spheres were brought into contact. (3)
10.3 Were electrons transferred from P TO Q or from Q TO P during contact? (1)
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