Q. 1. Which is bigger, a coulomb or charge on an electron? How many electric charges form one coulomb of charge?
Q. 2. A plastic comb run through ones dry hair attracts small bits of paper. Why? What happens if the hair is wet or if it raining?
Q. 3. What is an electric lines of force? What is its importance?
Q. 4. An ebonite rod held in hand can be charged by rubbing with flannel but a copper rod can’t be charged like this. Why?
Q. 5. What is the value of charge on an electron in S.I unit? Is a charge less than this value possible?
Q. 6. Define and explain quantisation of electric charge.
Q. 7. If a body gives out 109 electrons every second. How much time is required to get a total charge of 1C for of 1C from it? [Ans: - 198.2 year ]
Q. 8. A polythene piece rubbed with wool is found to have negative charge of 3.2 x 10-7C. Calculate the number of electrons transferred.
Q. 9. How is static electricity is different from current electricity?
Q. 10. Define current electricity. What do you mean by condition electrons?
Q. 11. Define electric current. “It has both direction as well as magnitude”, than why it is a scalar?
Q. 12. What is the current flowing through a conductor if one million electrons are crossing in 1 millisecond through a cross-section of it?
Q. 13. A wire is carrying a current. Is it charged?
Q. 14. A large number of free electrons are present in metals. Why is there no current in the absence of electric field across it?
Q. 15. When we switch on an electric bulb, it light almost instantaneously, though drift velocity of electron in wires is very small. Explain.
Q. 16. Define one example, one volt of potential energy.
Q. 17. A wire having resistance R is stretched so as to reduce it’s diameter to half of its previous value, what will be it’s new resistance?
Q. 18. What will be change in resistance of a Eureka Wire, when its radius is halved and length is reduces to one-forth of its original length? Explain why an electric bulb becomes dim when an electric heater in parallel circuit is made on. Why dimness decreases after some time?
Q. 19. Long distance power transmission is carried on high voltage lines. Why?
Q. 20. Which lamp has greater resistance a: 60w or 100w lamp, when connected to the same supply?
Q. 21. A wire of resistance 4R is bent in the form of circle. What is the effective resistance between ends of diameter?
