K.C.S.E Physics Q & A - MODEL 2001PP1QN09

K.C.S.E Physics Q & A - MODEL 2001PP1QN09

Fig. 7 shows “windmill” which when connected to the dome of a positively charged Van de Graff generator is observed to rotate as indicated. A, B, C and D are sharp points

Explain how this rotation is caused.

ANSWER

• Point action takes place at sharp points (A , B, C, D ), charge concentrates at sharp points causing high pd, this causes air the surrounding to be ionized. The positive ions are repelled causing points to move in opposite direction.