Download BASANT PHYSICS PHYSICS ASSIGNMENT CLASS – X Submit

BASANT PHYSICS
PHYSICS ASSIGNMENT
CLASS – X
Ph No.: 9777702608,
9861210706
Submit with in 7 days
Conceptual Question
1. Which is bigger, a coulomb or charge on an electron? How many
electric charges form one coulomb of charge?
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?
3. What is an electric lines of force? What is its importance?
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?
5. What is the value of charge on an electron in S.I unit? Is a charge less
than this value possible?
6. Define and explain quantisation of electric charge.
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
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.
9. How is static electricity is different from current electricity?
10. Define current electricity. What do you mean by condition electrons?
11. Define electric current. “It has both direction as well as magnitude”, than
why it is a scalar?
12. What is the current flowing through a conductor if one million electrons
are crossing in 1 millisecond through a cross-section of it?
13. A wire is carrying a current. Is it charged?
14. A large number of free electrons are present in metals. Why is there no
current in the absence of electric field across it?
15. When we switch on an electric bulb, it light almost instantaneously,
though drift velocity of electron in wires is very small. Explain.
16. Define one example, one volt of potential energy.
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?
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?
19. Long distance power transmission is carried on high voltage lines. Why?
20. Which lamp has greater resistance a: 60w or 100w lamp, when
connected to the same supply?
21. A wire of resistance 4R is bent in the form of circle. What is the
effective resistance between ends of diameter?
22. A wire of resistivety ζ is stretched to three times to length. What will be
its new resistivety?
23. Bends in a pipe slow down the flow of water through it. Do bends in a
wire increase its electrical resistance?
24. The V-I graph for conductor makes angle  with V-axis. Here V
denotes voltage and I denote current. What is the resistance of this
conductor?
[Ans: R = cot 
25. What are the factors on which the resistance of a conductor depends?
Give the corresponding relation.
26. To reduce the brightness of a light bulb, should an auxiliary resistance
be connected in series with it or in parallel?
27. Current is allowed to flow in a metallic wire at a constant potential
difference. When the wire becomes hot, cold water is poured on half of
its portion. By doing so, its other becomes still more hot. Explain its
reason.
28. What is super-conductivity? Write its two application.
29. Prove that in parallel combination of electrical applications, total power
consumption is equal to the sum of the powers of the individual
appliances.
30. A current in a circuit having constant resistance is tripled. How does this
effect the power dissipation?
31. A wire connected to a bulb glows when same current flows through
them. Why?
32. Nichrome and cupper wires of the same length and diameter are
connected in series in the electric circuit in which wire, the heat will be
produced at higher rate? Explain.
33. Draw V-I graph for an Ohmic and Non-Ohmic material. Give one
example for each.
34. How does the resistivety of (i) Conductor and (ii) A semiconductor vary
with temperature? Give reasons for each.
35. There is an impression among many people that a person touching a
high power line gets stuck with the line. Is that true? Explain.
36. Explain why an electric bulb becomes dim when an electric heater in
parallel circuit is made on. Why dimness decreases after some time?
37. Long distance power transmission is carried on high voltage lines. Why?
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