Fill in the blanks in the following statements:
(a) To draw water from a well we have to ——— at the rope.
(b) A charged body ———— an uncharged body towards it.
(c) To move a loaded trolley we have to ———— it.
(d) The north pole of a magnet ———— the north pole of another magnet.
(a) Pull
Pull or push is simply called as force. To draw water from a well, we have to pull whereas we have to apply push force on bucket to throw it in the well.
(b) Attracts
When a charged body attracts another charged or uncharged body towards it, is called as the electrostatic force of attraction.
(c) Push
If we want to change in the direction of trolley, we have to apply either push force or pull force on it. In the pull force, the direction changes in object is same to the applying force.
(d) Repels
Magnet have two poles: North and South. Same pole repels each other whereas opposite poles of magnet attracts each other.
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.
What is metamorphosis? Give examples.
Make a labelled diagram of a candle flame.
Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
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.
Make a sketch of the human nerve cell. What function do nerve cells perform?
Boojho made the following sketch (Fig. 17.29) of the solar system. Is the sketch correct? If not, correct it.
State the difference between eukaryotes and prokaryotes.
Mention against each of the following whether regular or diffused reflection will take place when a beam of light strikes. Justify your answer in each case.
(a) Polished wooden table (b) Chalk powder
(c) Cardboard surface (d) Marble floor with water spread over it
(e) Mirror (f) Piece of paper
Which zone of a flame does a goldsmith use for melting gold and silver and why?
Fill in the blanks:
(a) Burning of wood and coal causes of air.
(b) A liquid fuel, used in homes is .
(c) Fuel must be heated to its before it starts burning.
(d) Fire produced by oil cannot be controlled by .
If wheat is sown in the kharif season, what would happen? Discuss.
Give two examples of situations in which applied force causes a change in the shape of an object.
Discuss the effects of deforestation on the following:
(a) Wild animals
(b) Environment
(c) Villages (Rural areas)
(d) Cities (Urban areas)
(e) Earth
(f) The next generation
Phases of the moon occur because
(a) we can see only that part of the moon which reflects light towards us.
(b) our distance from the moon keeps changing.
(c) the shadow of the Earth covers only a part of moon’s surface.
(d) the thickness of the moon’s atmosphere is not constant.
What are the different ways in which water gets contaminated ?