Question 1. Five bulbs each of 100 watt capacity in a tunnel are illuminated continuously for twenty hours. The consumption of electricity will be _______.
(A) Twenty units
(B) Ten units
(C) Two units
(D) One unit
Question 2. The value of 1 kilowatt hour is ________.
(A) 105 J
(B) 103 J
(C) 3.6 × 103 J
(D) 3.6 × 106 J
Question 3. A 100 watt electric bulb is used for 10 hours. What will be the cost of electricity consumed, if the consumption cost is ` 5 per unit?
(A) ` 50
(B) ` 25
(C) ` 10
(D) ` 5
Question 4. If a bulb of 100 watt burns for 10 hours, the expenditure of electricity will be _____.
(A) 100 units
(B) 10 units
(C) 1 unit
(D) 0-1 unit
Question 5. An electric bulb of 100 watt is used for 4 hours. The unit of electric energy used is ________.
(A) 0.4
(B) 4
(C) 25
(D) 400
Question 6. How many units of electricity will be consumed if you use a 60 watt electric bulb for 5 hours everyday for 30 days?
(A) 3
(B) 6
(C) 9
(D) 12
Question 7. An electric bulb is connected to 220 V generator. The current is 0.5A. The power of the bulb is _______.
(A) 220 W
(B) 440
(C) 110 V
(D) 110 W
Question 8. Of the two bulbs in a house, one glows brighter than the other. In this context which of the following statements is correct?
(A) The dim bulb has larger resistance
(B) The bright bulb has larger resistance
(C) Both the bulbs have same the resistance
(D) The brightness does not depend on the resistance
Question 9. A dynamo which is said to generate electricity actually acts as a _______.
(A) Source of electrons
(B) Converter of energy
(C) Source of electric charge
(D) Source of ions
Question 10. Dynamo is a machine which is used for __________.
(A) Conversion of low voltage to high voltage
(B) Conversion of mechanical energy to electrical energy
(C) Conversion of electrical energy to mechanical energy
(D) Conversion of high voltage to low voltage
Question 11. Turbines and Dyanamos are used to convert which energy to electrical energy?
(A) Mechanical energy
(B) Magnetic energy
(C) Chemical energy
(D) Solar energy
Question 12. When electrical energy is converted into motion _________.
(A) Heat loss is 80 percent
(B) Heat loss is 30 percent
(C) Heat loss is 50 percent
(D) There is no heat loss
Question 13. . A device which converts electrical energy into mechanical energy is _________.
(A) Inductor
(B) Electric motor
(C) Transformer
(D) Dynamo
Question 14. A device which converts chemical energy into electrical energy is called _________.
(A) Moving coil meter
(B) Generator
(C) Motor
(D) Battery
Question 15. Electric motors operating at low voltages tend to burn out because ________.
(A) Low voltage sets in electrical discharge
(B) They draw heat proportional to v 2
(C) They draw more current which is inversely proportional to the square root of the voltage
(D) They draw more current which is inversely proportional to the voltage
Question 16. Which of the following metals is used as filament in lighting bulbs?
(A) Tungsten
(B) Silver
(C) Molybdenum
(D) Iron
Question 17. The temperature of the filament of lighted electric bulb is generally_______.
(A) 3000ºC to 3500ºC
(B) 2000ºC to 2500ºC
(C) 1000ºC to 1500ºC
(D) 100ºC to 500ºC
Question 18. Which gas is filled in normal tube light?
(A) Mercury vapour with neon
(B) Mercury vapour with argon
(C) Sodium vapour with neon
(D) Sodium vapour with argon
Question 19.What is the order of magnitude of electric resistance of the human body (dry)?
(A) 108 ohm
(B) 106 ohm
(C) 104 ohm
(D) 102 ohm
Question 20. A wire with black insulation during electric supply is _______.
(A) Fuse wire
(B) Neutral wire
(C) Earth wire
(D) Live wire
Question 21. Domestic electrical wiring is basically a ________.
(A) Series connection within each room and parallel connective elsewhere
(B) Combination of series and parallel connections
(C) Parallel connection
(D) Series connection
Question 22. The filament of a halogen lamp is an alloy of _______.
(A) Molybdenum and sodium
(B) Tungsten and sodium
(C) Tungsten and bromine
(D) Tungsten and iodine
Question 23. Fuse wire used for safety of household have ______.
(A) Low melting point
(B) High resistance
(C) High melting point
(D) Both (A) and (B)
Question 24. A fuse wire is characterized by ____.
(A) High resistance and high melting point
(B) High resistance and low melting point
(C) Low resistance and low melting point
(D) Low resistance and high melting point
Question 25. Principle of fuse is _____.
(A) Magnetic effect of electricity
(B) Heating effect of electricity
(C) Mechanical effect of electricity
(D) Chemical effect of electricity
Question 26. A fuse is used in main electric supply as a safety device. Which one of the following statements about the fuse is correct?
(A) It must have a very high resistance
(B) It must have a low melting point
(C) It is made mainly from silver alloys
(D) It is connected in parallel with the main switch
Question 27. Which element is the best conductor of electricity?
(A) Iron
(B) Aluminium
(C) Copper
(D) Silver
Question 28. The electric current does not flow between two properly connected charged bodies if they are having ______.
(A) Same potential
(B) Same resistivity
(C) Same capacity
(D) Same charge
Question 29. In electric apparatus ‘Earth’ is used?
(A) In the form of fuse
(B) For safety
(C) Because the apparatus used 3-phase
(D) To reduce the expenditure
Question 30. In a three-pin electrical plug longest pin should be connected to ________.
(A) Any terminal
(B) Neutral terminal
(C) Live terminal
(D) Ground terminal