Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 13 (60 MCQs)

Quiz Instructions

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1. ..... instrument is used to measure the voltage.
2. Electonic current flows from positive to negative?
3. Like poles of a magnet will
4. The distance between a positively charged object and a negatively charged object increases. If everything else remains constant, what happens to the electric force between the objects?
5. The magnetic field lines inside a current carrying solenoid, are:
6. Position of a key or a switch in a circuit is
7. The direction of magnetic field lines due to a straight current carrying conductor B is given by:
8. The acting contacts for circuit breakers are made of
9. In making a battery(a) the positive terminal of one cell is connected to the negative terminal of the next cell(b) the positive terminal of one cell is connected to the positive terminal of the next cell(c) the negative terminal of one cell is connected to the negative terminal of the next cell(d) none of the above
10. If the current through the coil stops flowing. Will the coil remain an electromagnet?
11. What would happen if you add more batteries to an electrical circuit containing light bulbs?
12. The direction of magnetic field is given by which of the following rule
13. Who discovered the relationship between electricity and magnetism?
14. The device used to make or break an electric circuit is
15. When do we use a battery?
16. The term is used for the mode of nutrition in yeast, mushroom and bread-mould is
17. Water containing which of the following substances may conduct electricity
18. What charge do protons have?
19. Which of the following is most ecofriendly?
20. The ..... of the magnetic field is shown by the degree of closeness of the field lines.
21. The axis of Earth's magnet field is inclined with geographical axis at an angle of about:
22. Chromium corrodes easily.
23. Which of the following principles explains how an electric motor works?
24. What is the function of a dry cell?
25. Waste from an electroplating factory must be disposed off
26. An object through which electrons can easily flow is called a(n) .....
27. What is full form of MRI?
28. N a potentiometer of 10 wires, the balance point is obtained on the 7th wire. To shift the balance point to 9th wire, we should
29. Ocean currents transport matter and energy. Besides water, ocean currents also carry important matter such as ..... , ..... and ..... necesary for the survival of marine organisms.
30. Poor conductor of electricity
31. You close the switch to turn on a device or to turn on a light.True or false
32. What is the use of electrolysis-
33. Electromagnets are not used to lift heavy loads.
34. A student drops some nails into a trash can half filled with wood shavings. Which is a way to separate the mixture of nails and shavings?sifting
35. Full form of-CFL
36. An electric bulb is an example of the heating effect of an electric current
37. Temperature and salinity differences in ocean water cause:
38. Name the scientist who discovered electromagnetism.
39. When does an electromagnet lose its magnetic Property?
40. Which of the following is being used in place of fuses?
41. Which part of a circuit starts and stops the flow of electrical current?
42. How many terminals a cell has
43. When an electric current flows through the wire it gets heated it is known as the heater
44. One disadvantage for physiological effects of electric current
45. The amount of heat H produced in time t is
46. The positive ions are known as-
47. In the following formula, what represents the charge?
48. Which type of material DOES NOT allow electric current to flow through it?
49. A student conducts an experiment by dropping a ball from different heights and measuring the time it takes to hit the ground. What is the independent variable in this experiment?
50. Choose insulator from the following:
51. A combination of two or more cells is called ( )
52. Which of the following best describes the law of conservation of energy?
53. The electric bell makes use of
54. What is the current through a 11V bulb with a power of 99W?
55. If the number of turns in a coil is increased then the magnetic field produced by it will:
56. An electric current that has constant magnitude and direction over time is known as a(n)
57. On what principle is electric bell based?
58. The combination of two or more cells is known as:-
59. The thicker wire has low resistance because ..... electric charges can flow through it.
60. Which among the following is the disadvantage of heating effect of current?