11. Electricity

*नोट: यह सेक्शन रिवीजन के लिए है। अपना ज्ञान परखने के लिए ऊपर दिए गए क्विज़ में भाग लें।

1. What is the SI unit of Electric Current?
   A) Volt  |  B) Ohm  |  C) Ampere  |  D) Watt
2. What is the SI unit of Charge?
   A) Joule  |  B) Coulomb  |  C) Ampere  |  D) Volt
3. Which instrument is used to measure Electric Potential Difference?
   A) Ammeter  |  B) Voltmeter  |  C) Galvanometer  |  D) Thermometer
4. In which order is an Ammeter connected in a circuit?
   A) Series  |  B) Parallel  |  C) Both  |  D) None of these
5. How much charge is on an electron?
   A) 1.6 x 10^-19 C  |  B) 1.6 x 10^19 C  |  C) 9.1 x 10^-31 C  |  D) 1 C
6. The component used to regulate current in a circuit is called:
   A) Voltmeter  |  B) Variable resistance (Rheostat)  |  C) Ammeter  |  D) Connecting wire
7. What is the SI unit of Resistance?
   A) Ohm (Ω)  |  B) Watt  |  C) Ampere  |  D) Volt
8. The SI unit of Electric Power is:
   A) Joule  |  B) Ohm  |  C) Watt  |  D) Coulomb
9. One unit of electric energy is equal to:
   A) 1 kWh  |  B) 1 Wh  |  C) 1000 J  |  D) 3.6 J
10. The filament of an electric bulb is made of which metal?
    A) Iron  |  B) Copper  |  C) Tungsten  |  D) Nichrome
11. Ohm's Law in the form of a formula is:
    A) V = I/R  |  B) V = IR  |  C) I = VR  |  D) R = VI
12. What remains same when resistors are connected in parallel?
    A) Electric current  |  B) Potential Difference (Voltage)  |  C) Resistance  |  D) Power
13. An electric fuse is based on:
    A) Magnetic effect of current  |  B) Heating effect of current  |  C) Chemical effect  |  D) None of these
14. The coil of an electric heater is made of which substance?
    A) Tungsten  |  B) Nichrome  |  C) Iron  |  D) Silver
15. How is a Voltmeter connected in a circuit to measure potential difference?
    A) Series  |  B) Parallel  |  C) Both  |  D) None of these
16. The direction of electric current is considered to be:
    A) In direction of electron flow  |  B) Opposite to the direction of electron flow  |  C) Any direction  |  D) Static
17. 1 Ampere is equal to:
    A) 1 Joule/second  |  B) 1 Coulomb/second  |  C) 1 Volt/Ohm  |  D) Both B and C
18. The resistance of a conductor does NOT depend on:
    A) Length  |  B) Area of cross-section  |  C) Nature of material  |  D) Shape of conductor
19. What is the formula for Electric Energy (E)?
    A) P x t  |  B) V x I x t  |  C) I^2 x R x t  |  D) All of the above
20. Power P is equal to:
    A) VI  |  B) I^2 R  |  C) V^2 / R  |  D) All of the above
21. If the length of a conductor is doubled, what will happen to its resistance?
    A) Halved  |  B) Doubled  |  C) Four times  |  D) Remains same
22. What is the unit of Resistivity?
    A) Ohm  |  B) Ohm-meter (Ωm)  |  C) Ohm/meter  |  D) Ampere
23. The total resistance (Rs) of resistors connected in series is:
    A) R1 + R2 + R3  |  B) 1/R1 + 1/R2  |  C) R1 x R2  |  D) Zero
24. How does increasing the area of cross-section of a conductor affect its resistance?
    A) Increases  |  B) Decreases  |  C) Remains same  |  D) Becomes zero
25. In which order are electrical appliances connected in houses?
    A) Series  |  B) Parallel  |  C) Mixed  |  D) None of these
26. What is Joule's law of heating?
    A) H = VIt  |  B) H = I^2 Rt  |  C) H = (V^2/R)t  |  D) All of the above
27. Why are heating elements of toasters and irons made of alloys rather than pure metals?
    A) Being cheaper  |  B) Alloys have higher resistivity and melting point  |  C) They look beautiful  |  D) None of these
28. How many Joules are in 1 kWh?
    A) 3.6 x 10^5 J  |  B) 3.6 x 10^6 J  |  C) 1000 J  |  D) 3600 J
29. Which gases are filled in electric bulbs to prevent oxidation of the filament?
    A) Oxygen  |  B) Nitrogen and Argon  |  C) Hydrogen  |  D) CO2
30. If two resistors of 10 Ω are connected in parallel, the equivalent resistance will be:
    A) 20 Ω  |  B) 5 Ω  |  C) 1 Ω  |  D) 10 Ω
31. The V-I graph of a conductor is a straight line. What does this indicate?
    A) Resistance is changing  |  B) Ohm's law is being followed  |  C) Voltage is constant  |  D) None of these
32. What should be the property of an electric fuse wire?
    A) High melting point  |  B) Low melting point  |  C) Very thick  |  D) None of these
33. On increasing the temperature of semiconductors, their resistance:
    A) Increases  |  B) Decreases  |  C) Remains same  |  D) Becomes zero
34. On which factor does resistivity depend?
    A) Length  |  B) Thickness  |  C) Nature of material and temperature  |  D) Shape
35. Why is an Ammeter always connected in series in a circuit?
    A) For high resistance  |  B) So that total current can flow through it (low resistance)  |  C) For beauty  |  D) None of these
36. What should be the resistance of a Voltmeter?
    A) Zero  |  B) Very high  |  C) Low  |  D) Medium
37. If three resistors of 2 Ω, 3 Ω and 5 Ω are in series, what will be the total resistance?
    A) 10 Ω  |  B) 1.0 Ω  |  C) 30 Ω  |  D) 0 Ω
38. From the formula P = V^2 / R, it is clear that at constant voltage, power and resistance are:
    A) Directly proportional  |  B) Inversely proportional  |  C) No relation  |  D) Same
39. Substances that offer very little hindrance to the flow of current are:
    A) Insulators  |  B) Conductors  |  C) Semiconductors  |  D) Dielectrics
40. What is the main advantage of parallel combination?
    A) If one appliance fails, others keep working  |  B) Voltage remains same  |  C) Both A and B  |  D) No advantage
41. Superconductors are substances whose resistance at very low temperatures becomes:
    A) Infinite  |  B) Zero  |  C) One  |  D) Constant
42. The power of a bulb is 100W and voltage is 220V. What will be its resistance?
    A) 484 Ω  |  B) 2.2 Ω  |  C) 100 Ω  |  D) 2200 Ω
43. What will be the equivalent resistance of 'n' equal resistors (each R) connected in parallel?
    A) nR  |  B) R/n  |  C) R^n  |  D) n/R
44. With which wire is the electric fuse connected in a circuit?
    A) Neutral wire  |  B) Live wire  |  C) Earth wire  |  D) Any
45. If a wire is stretched to double its length, its new resistance will be:
    A) 2 times  |  B) 4 times (due to half area)  |  C) Same  |  D) Half
46. The device that produces electric current is called:
    A) Generator  |  B) Galvanometer  |  C) Ammeter  |  D) Motor
47. Which reaction inside a battery produces potential difference?
    A) Physical  |  B) Chemical reaction  |  C) Biological  |  D) Nuclear
48. How many Amperes are in 1 milli-ampere (mA)?
    A) 10^3 A  |  B) 10^-3 A  |  C) 10^-6 A  |  D) 10 A
49. Nichrome is an alloy of which metals?
    A) Ni, Cr, Mn, Fe  |  B) Cu, Zn  |  C) Cu, Sn  |  D) Fe, C
50. What is the approximate melting point of Tungsten?
    A) 1000°C  |  B) 3380°C  |  C) 1500°C  |  D) 500°C
51. Is the value of current same in each resistor in a series combination?
    A) Yes  |  B) No  |  C) Only in the first one  |  D) Depends on voltage
52. Current of 0.5 A flows in a conductor for 2 minutes. What will be the charge?
    A) 1 C  |  B) 60 C (Q=It)  |  C) 0.5 C  |  D) 120 C
53. How is the graph between potential difference V and current I?
    A) Circular  |  B) Straight line passing through origin  |  C) Curved line  |  D) None of these
54. The resistivity of insulators (like glass, rubber) is of the order of:
    A) 10^-8 Ωm  |  B) 10^12 to 10^17 Ωm  |  C) 1 Ωm  |  D) 0
55. Continuous flow of electrons is called:
    A) Static electricity  |  B) Electric Current  |  C) Magnetism  |  D) Power
56. Resistance of a conductor is 5 Ω. If 10 V potential is applied, current will be:
    A) 50 A  |  B) 2 A  |  C) 0.5 A  |  D) 15 A
57. On which does resistivity NOT depend?
    A) Material  |  B) Temperature  |  C) Length and thickness of conductor  |  D) Purity
58. The resistivity of Silver compared to Copper is:
    A) More  |  B) Less (Silver is the best conductor)  |  C) Same  |  D) None of these
59. The industrial unit of electric power (in practice) is:
    A) Watt  |  B) Horse Power (HP)  |  C) Joule  |  D) Coulomb
60. 1 Horse Power (H.P.) is equal to:
    A) 1000 W  |  B) 746 W  |  C) 500 W  |  D) 100 W