Match the items given in Column I with one or more items of Column II.
Column I Column II
(a) A plane mirror (i) Used as a magnifying glass.
(b) A convex mirror (ii) Can form image of objects spread over a large area.
(c) A convex lens (iii) Used by dentists to see enlarged image of teeth.
(d) A concave mirror (iv) The image is always inverted and magnified. (e) A concave lens (v) The image is erect and of the same size as the object.
(vi) The image is erect and smaller in size than the object.
Column I Column II
(a) A plane mirror (v) The image is erect and of the same size as the object.
(b) A convex mirror (ii) Can form image of objects spreads over a large area.
(c) A convex lens (i) Used as a magnifying glass.
(d) A concave mirror (iii) Used by dentists to see enlarged image of teeth.
(e) A concave lens (vi) The image is erect and smaller in size than the object.
1. A plane mirror: A plane mirror have a flat reflective surface. The angle of reflection is always equals to the angle of incidence for the light rays which strikes the plane mirror. The angle formed by the incident ray and surface of normal is called the angle of incidence.
2. A convex mirror: A convex mirror is a diverging mirror in which the reflective surface bulges towards the light Source. The image formed by convex mirrors are smaller than the object but gets larger as they approach.
3. Concave mirror: A concave mirror has a reflective surface that is curved inwards and away from the light source. Concave mirrors are widely used in headlights of auto mobiles motor vehicles, torch lights etc.
4. Convex lens: The convex lens is a lens that converges rays of light that convey parallel to its principal axis which is relatively thick cross the middle and thin at the lower and upper edges. A convex lense in thinner in the middle and thicker towards the edges.
5. Concave lens: A concave lens is a lens that possesses at least one surface that curves inwards. It is a diverging lens, meaning that it spreads out light rays that have been refracted through it. A concave lens is thinner at its edges, and is used to correct short sightedness.
State two differences between a convex and a concave lens.
David is observing his image in a plane mirror. The distance between the mirror and his image is 4 m. If he moves 1 m towards the mirror, then the distance between David and his image will be
(i) 3 m (ii) 5 m
(iii) 6 m (iv) 8 m
Give one use each of a concave and a convex mirror.
Fill in the blanks:
(a) An image that cannot be obtained on a screen is called ____________.
(b) Image formed by a convex __________ is always virtual and smaller in size.
(c) An image formed by a __________ mirror is always of the same size as that of the object.
(d) An image which can be obtained on a screen is called a _________ image.
(e) An image formed by a concave ___________ cannot be obtained on a screen.
The rear view mirror of a car is a plane mirror. A driver is reversing his car at a speed of 2 m/s. The driver sees in his rear view mirror the
image of a truck parked behind his car. The speed at which the image of the truck appears to approach the driver will be
(i) 1 m/s (ii) 2 m/s
(iii) 4 m/s (iv) 8 m/s
Find out the letters of English alphabet or any other language known to you in which the image formed in a plane mirror appears exactly like the letter itself. Discuss your findings.
11. A virtual image larger than the object can be produced by a
(i) concave lens (ii) concave mirror
(iii) convex mirror (iv) plane mirror
What is a virtual image? Give one situation where a virtual image is formed.
Which type of lens forms always a virtual image?
Mark 'T' if the statement is true and 'F' if it is false:
(a) We can obtain an enlarged and erect image by a convex mirror. (T/F)
(b) A concave lens always form a virtual image. (T/F)
(c) We can obtain a real, enlarged and inverted image by a concave mirror. (T/F)
(d) A real image cannot be obtained on a screen. (T/F)
(e) A concave mirror always form a real image. (T/F)
State similarities and differences between the laboratory thermometer and the clinical thermometer.
State differences between acids and bases.
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food
Name the elements that determine the weather of a place.
Fill the missing word in the blank spaces in the following statements:
(a) Wind is——————air.
(b) Winds are generated due to —————— heating on the earth.
(c) Near the earth’s surface __________air rises up whereas ___________ air comes down.
(d) Air moves from a region of ——— pressure to a region of ———.
In addition to the rock particles, the soil contains
(i) air and water
(ii) water and plants
(iii) minerals, organic matter, air and water
(iv) water, air and plants
Why does an athlete breathe faster and deeper than usual after finishing the race?
Match structures given in Column I with functions given in Column II.
Column I Column II
(i) Stomata (a) Absorption of water
(ii) Xylem (b) Transpiration
(iii) Root hairs (c) Transport of food
(iv) Phloem (d) Transport of water
(e) Synthesis of carbohydrates
Fill in the blanks:
(a) Production of new individuals from the vegetative part of parent is called_____________.
(b) A flower may have either male or female reproductive parts. Such a flower is called_____________.
(c) The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as _____________.
(d) The fusion of male and female gametes is termed as _____________.
(e) Seed dispersal takes place by means of _____________, _____________ and _____________.
Classify the following as motion along a straight line, circular or oscillatory motion:
(i) Motion of your hands while running.
(ii) Motion of a horse pulling a cart on a straight road.
(iii) Motion of a child in a merry-go-round.
(iv) Motion of a child on a see-saw.
(v) Motion of the hammer of an electric bell.
(vi) Motion of a train on a straight bridge.
What are the components of blood?
List the differences between clayey soil and sandy soil.
Which features adapt polar bears to live in extremely cold climate?
(i) A white fur, fat below skin, keen sense of smell.
(ii) Thin skin, large eyes, a white fur.
(iii) A long tail, strong claws, white large paws.
(iv) White body, paws for swimming, gills for respiration.
How would you test the presence of starch in leaves?
When are the maximum and minimum temperatures likely to occur during the day?
Sketch the reproductive parts of a flower.
Show with the help of a sketch that the plants are the ultimate source of food.
What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas.
Draw the circuit diagram to represent the circuit shown in Fig.14.21.
Match the items in Column I with those in Column II:
Column I Column II
(a) Yeast (i) Earthworm
(b) Diaphragm (ii) Gills
(c) Skin (iii) Alcohol
(d) Leaves (iv) Chest cavity
(e) Fish (v) Stomata
(f) Frog (vi) Lungs and skin
(vii) Tracheae