Four children were asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. Their arrangements are given below. Choose the correct arrangement.
(a) Rolling, static, sliding
(b) Rolling, sliding, static
(c) Static, sliding, rolling
(d) Sliding, static, rolling
(c) Static, sliding, rolling
Static > sliding > rolling
Because in rolling the interlocking time between two surfaces are very less as compared to the sliding and static friction. In static friction, the interlocking time between two surfaces are greater. So, static friction is higher than sliding and rolling friction. The area of contact is very less in rolling friction as compare to static and sliding friction.
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.
Make a labelled diagram of a candle flame.
What is menstruation? Explain.
Explain why a charged body loses its charge if we touch it with our hand.
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. ( )
Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain.
Make sketches of animal and plant cells. State three differences between them.
Explain how CO2 is able to control fires.
Explain how you can take care of your eyes.
What is the difference between noise and music? Can music become noise sometimes?
Make a sketch of the human nerve cell. What function do nerve cells perform?