Explain why objects moving in fluids must have special shapes.
When a body moves in fluid, it experiences a force of friction called a drag force. It fluids, to overcome the frictional force, objects given special shapes. Frictional force can be minimized by changing in shape of the object. The special shape of the body exerts less friction and move easily in the fluid. That’s why objects moving in fluids must have special shapes.
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.
Describe the construction of a kaleidoscope.
Compare LPG and wood as fuels.
The weather department has predicted that a thunderstorm is likely to occur on a certain day. Suppose you have to go out on that day. Would you carry an umbrella? Explain.
Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain.
In case of a fire, before the firemen use the water hoses, they shut off the main electrical supply for the area. Explain why they do this.
How is an embryo developed?
Explain how you can locate the Pole Star with the help of Ursa Major.
Choose the correct answer :
Sound can travel through
(a) gases only (b) solids only
(c) liquids only (d) solids, liquids and gases.
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.
Draw a labeled sketch of the human eye.