Question

1) Veena has read that some substances are good conductors of electricity where as some are bad
conductors. Among the following which substance is good conductor of electricity?
a) Copper
b) Silver
2) Today Rohit came to know that in the ancient times people used a device to detect direction what
c) Iron
d) All of the above
was that device called?
a) Voltmeter
b) Ammeter c) Magnetic Compass
3. Manish today read about various effects of electric current Electric bulb works on which effect of
d) All of the above
electric current?
a) Heating effect b) Magnetic effect
4. Neeta's mother today brought gold plated silver Jewelry. What is the process of plating one metal
c) Chemical effect d) All of the above
on another metal called?
a) Vaporization b) Electroplating
c) Distillation
c) All of the above
5) Dhruv was very happy to see traffic signals in the city. What kinds of lights are used in traffic
signals?
a) Tungsten bulb b) LED bulb
c) Neon bulb
d) None of the above
6. Meenakshi broke a dry cell today. She got a black colored rod from it. What is this rod called?
a) Electrode
b) Electrolyte c) Insulator
d) All of the above
7. Heera singh is surprised that the flow of electric current breaks the water into hydrogen and
oxygen. Can you tell me that due to which effect of current this happens?
a) Heating effect b) Chemical effect c) Magnetic effect d) All of the above
8. Today Baljinder saw in science lab that lemon juice is good conductor of electricity. Among the
following which is good conductor of electricity?
a) Vinegar
b) Tap water c) Tomato juice d) All of the above
9. Electricity repair is going on at sewak's house. He saw that handles of electrical repairing tools are
made up of plastic. What is the reason for this?
b) Plastic is bad conductor of electricity
a) Plastic is good conductor of electricity
d) None of the above.
c) Plastic generates electricity
10. Pankaj knows that pure water is bad conductor of electricity. If you dissolve salt in water what will
happen?
a) Water will become good conductor of electricity.
b) Water will become bad conductor of electricity.
c) Water will neither become good conductor nor bad conductor.
d) None of the above.
11. Sanjeev noted that there is layer of another metal on iron vehicles. Why is this done?
b) To increase the strength of iron.
a) To prevent rusting
d) All of the above.
c) To make the surface shiny.
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Answer 1

Answer:

1.silver

2. magnetic compass

3.heating effect

4.electroplating

5.neon bulb

6.electrorode

7.chemical effect

8.vinegar

9.plastic is a bad conductor of electricity

10.b.

11.d.

Answer 2

Answer:

1. b) Silver

➛ Silver is the best conductor of heat and electricity followed by copper and aluminium.

2. c) Magnetic Compass

➛ Magnetic compass is an instrument that is used in navigation for determining the direction on the surface of the earth.

3. c) Chemical effect

➛ In the cell, the chemical energy maintains one end at high potential and other at lower potential. In a way that chemical energy of cell changes into kinetic energy of electrons. This kinetic energy of electron is commonly called electrical energy.

4. b) Electroplating

➛ Electroplating is a process in which one metal is coated on another metal the process of electro-deposition.

5. c) Neon

➛ They emit different colours which are very attractive. They are also used in advertisement purpose.

6. b) Electrolyte

➛ The black road of the cell, is a carbon rod. It is a anode of the cell as it acts as the positive terminal of the cell.

7. b) Chemical effect

➛ When electric current is passed through water water decomposes into hydrogen and oxygen it is the chemical effect of current.

8. a) Vinegar

➛ Vinegar is good conductor of electricity

9. b) Plastic is bad conductor of electricity

➛ Plastic acts as a insulator not a conductor.

10. a) Water will become good conductor of electricity.

➛ It is a good conductor of electricity because salt contains ions as sodium chloride (NaCl) dissolved in the water.

11. d) All of the above.

➛ There is layer of another metal on iron vehicles to increase the strength of iron, so that it can last longer, to prevent rusting for longer usage and to make the surface shiny for its appearance.

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