4 Spray painting uses electrostatics to: A Reduce paint usage B Increase heat C Produce sound D Increase voltage
6 The breakdown strength of air is approximately: A 3 × 10^6 V/m B 3 × 10^3 V/m C 3 × 10^9 V/m D 3 × 10^2 V/m
7 Which factor does electric field strength depend on? A Charge only B Distance only C Charge and distance D Mass
9 Divergence of gold leaves indicates: A No charge B Presence of charge C Loss of charge D Magnetic effect
10 Which law explains force between charges? A Ohm’s law B Faraday’s law C Coulomb’s law D Newton’s law
12 Electrical breakdown of air occurs when: A Air becomes cold B Electric field exceeds a critical value C Humidity increases D Pressure decreases
13 Gold leaves are used in an electroscope because they are: A Heavy B Elastic C Good conductors D Magnetic
14 Corona discharge occurs when: A Field is very weak B Field is slightly below breakdown value C Field is zero D No charge is present
15 What happens during discharging? A Charge increases B Charge remains constant C Charge flows away D New charge is produced
17 Which factor does NOT affect charging by friction? A Nature of materials B Roughness of surface C Speed of rubbing D Color of objects
18 What is an electric field? A Region of magnetic force B Region around a charge where force is felt C Flow of electrons D Electric current