Question

The electric field inside a Van de Graff generator becomes

• A. high enough to ionize air molecules
• B. high enough to ionize vacuum
• C. low enough to ionize air molecules
• D. low enough to ionize vacuum

Answer 1

The correct option is A high enough to ionize air molecules

The electric field inside the Van de Graff generator becomes high enough to ionize the air molecules. The method of charging used in this generator is triboelectric effect due to which rubber of the belt becomes negatively charged while upper roller becomes positively charged. The electric field surrounding the upper positive roller induces a high electric field near the points of the necessary comb. At the points, the field becomes strong enough to ionize the air molecules.