Fill in the blanks
(a) Most liquids that conduct electricity are solutions of , ______________ and ______________.
(b) The passage of an electric current through a solution causes ______________ effects.
(c) If you pass current through copper sulphate solution, copper gets deposited on the plate connected to the terminal of the battery.
(d) The process of depositing a layer ofany desired metal on another material by means of electricity is called .
(a) Acids and bases, salts
Some of the acidic, basic and neutral solutions also conduct electricity. They allow the current to pass through them.
(b) Chemical
When current passes through a solution, it dissociate into ions, i.e. positive and negative ions. The process of decomposition of the solution is called as chemical effect.
(c) Negative
The solution dissociate into positively charges copper ions and negatively charged sulfate ions, when we pass electricity or current through a copper sulfate solution. Positively charged copper ions attached to plate which is connected to the negative terminal of the battery.
(d) Electroplating
Electroplating is done on metals, to prevent them from the rusting with the help of electricity.
Describe with the help of a diagram an instrument which can be used to detect a charged body.
Sketch larynx and explain its function in your own words.
Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
Make a labelled diagram of a candle flame.
What is metamorphosis? Give examples.
The following Table shows the total power shortage in India from 1991– 1997. Show the data in the form of a graph. Plot shortage percentage for the years on the Y-axis and the year on the X-axis.
Make sketches of animal and plant cells. State three differences between them.
What is a constellation? Name any two constellations.
Describe the construction of a kaleidoscope.
Complete the crossword with the help of clues given below:
Across
1. This is necessary for photosynthesis.
3. Term for component present in the cytoplasm.
6. The living substance in the cell.
8. Units of inheritance present on the chromosomes.
Down
1. Green plastids.
2. Formed by collection of tissues.
4. It separates the contents of the cell from the surrounding medium.
5. Empty structure in the cytoplasm.
7. A group of cells.
Explain why the sliding friction is less than the static friction.
Can the process of rusting be called combustion? Discuss.
Mark the following statements as true (T) or false (F):
(a) Pole Star is a member of the solar system. ( )
(b) Mercury is the smallest planet of the solar system. ( )
(c) Uranus is the farthest planet in the solar system. ( )
(d) INSAT is an artificial satellite. ( )
(e) There are nine planets in the solar system. ( )
(f) Constellation Orion can be seen only with a telescope. ( )
Name the unit in which the calorific value of a fuel is expressed.
Prepare a Table having two columns depicting names of endocrine glands and hormones secreted by them.
Sketch larynx and explain its function in your own words.
Which part of the cell contains organelles?
Explain how fertilisers are different from manure.
When we press the bulb of a dropper with its nozzle kept in water, air in the dropper is seen to escape in the form of bubbles. Once we release the pressure on the bulb, water gets filled in the dropper. The rise of water in the dropper is due to
(a) pressure of water
(b) gravity of the earth
(c) shape of rubber bulb
(d) atmospheric pressure
Boojho made the following sketch (Fig. 17.29) of the solar system. Is the sketch correct? If not, correct it.