Q 1 – Which of the following is a bad conductor of electricity?
(a) Distilled water
(b) Silver nitrate
(c) Sulphuric acid
(d) Copper sulphate
Q 2 – An electric current can produce
(a) heating effect
(b) chemical effect
(c) magnetic effect
(d) all of these
Q 3 – Which of the following is a good conductor?
(a) Brick
(b) Steel
(c) Plastic
(d) Cotton
Q 3 – Which of the following is a good conductor?
(a) Brick
(b) Steel
(c) Plastic
(d) Cotton
Q 4 – Electroplating is based on
(a) heating effect of electricity
(b) chemical effect of electricity
(c) physical effect of electricity
(d) magnetic effect of electricity
Q 5 – Waste from an electroplating factory must be disposed off
(a) in the nearby river
(b) in the nearby pond
(c) in the nearby cornfield
(d) according to the disposal guidelines of Waste Management Bodies
Q 5 – Waste from an electroplating factory must be disposed off
(a) in the nearby river
(b) in the nearby pond
(c) in the nearby cornfield
(d) according to the disposal guidelines of Waste Management Bodies
Q 6 – Which is not a non-electrolyte?
(a) Ethyl alcohol
(b) Sodium chloride
(c) Urea
(d) Sodium solution
Q 7 – Electroplating prevents
(a) corrosion
(b) passing of current
(c) dissociation
(d) shining
Q 8 – Electric poles are coated with a layer of which metal?
(a) Chromium
(b) Zinc
(c) Silver
(d) Aluminium
Q 9 – Chemical effects of electric current are primarily used for which of the following?
(a) Electroplating
(b) Separating oxygen
(c) Separating hydrogen
(d) Separating gold
Q 10 – The glowing of the filament of a bulb is due to
(a) heating effect of electric current
(b) physical effect of electric current
(c) magnetic effect of electric current
(d) chemical effect of electric current
Q 11 – Fill in the blanks
- A cation has ……………… charge.
- Some liquids are ……………… conductors of electricity and some are ……………… conductors of electricity.
- Distilled water is an ………………
- Distilled water when mixed with salts becomes a ……………… conductor of electricity.
- Light emitting diodes (LED) glow even when a ……………… electric current flows through it.
Q 12 – True or false
- Rubber is a good conductor of electricity.
- Plastics are poor conductor of electricity.
- Pure water conducts electricity.
- Electroplating is based on magnetic effect of electricity.
- An electric bulb glows due to chemical effect of electricity.
Q 13 – Match the following
Column A | Column B |
1. Insulator circuit | (a) Electric |
2. Conductor | (b) Conducts current |
3. Closed path | (c) Prevents rusting |
4. Solution of distilled water and salt | (d) Rubber |
5. Electroplating | (e) Copper |
Q 14 – Is water from taps, handpumps, wells and ponds a good conductor?
Q 15 – Why is tin electroplated on iron to make cans used for storing food?
Q 16 – Name the three effects of electric current.
Q 17 – Define good conductors and poor conductors or insulators.
Q 18 – How is the conductivity of liquids tested?
Q 19 – Show with the help of a diagram that lemon juice and vinegar are good conductors of electricity.
Q 20 – What is an LED? Why is it preferred to other type of bulbs?
Q 21 – Explain the conductivity of water.
or
Normal water conducts electricity while the pure or distilled water does not. Explain why?
Q 22 – What happens when electric current is passed through the copper sulphate solution?
Q 23 – How does a bulb glow in liquid? Explain.
Q 24 – What happens when an electric current is passed through a cut potato for a considerable time?
Q 25 – Why is chromium used for electroplating? Why the objects have chromium plating are not made of chromium itself?
Q 25 – Why is chromium used for electroplating? Why the objects have chromium plating are not made of chromium itself?
Q 26 – Which metals, except chromium, are used for electroplating other metals?