IMPORTANT CLASS X

Parents and students are invited for Career Counselling. One to One interaction with Principal.
Timings : 10:30 am onwards on 27th feb (Wednesday).

CLASS X:IMPORTANT QUESTIONS: BIOLOGY

1.Name the gas which is a major component of biogas. Write its chemical formula too.
2. Name the organism(s) belonging to fourth trophic level in the food chain comprising of:
Snakes, Insects, Frogs, Plants, Hawks
3. Name the chemical compound which depletes ozone layer.
4. What is meant by DNA copying? Mention its importance in reproduction?
5. Write two advantages of vegetative propagation?
6. Why should fossil fuels be used judiciously? Write any two reasons.
7. Name the three `R’ s to save environment. Explain any one with the help of one example.
8. Draw the labelled diagram of female reproductive system. Name the organ which provides nutrition to embryo? Where is it located?
9. In human beings, the statistical probability of getting either a male or a female child is 50:50. Give reasons and explain with the help of diagram.
10. Differentiate between homologous and analogous organs. Give one example of each.
11. What are fossils? How is life of a fossil estimated ?
12. (a) Draw a labelled diagram of longitudinal section of flower
(b) Name the male and female reproductive part in a bi-sexual flower. Explain function of each in brief .
13. (a) Draw a labelled diagram of germination of pollen on stigma
(b) Explain the process of germination.
14. Write any two effects of Ozone depletion on our health.
15. Explain with example the importance of variation in the species
16. How is the process of binary fission in Amoeba different to that in Leishmania ?
17. Define water harvesting. List two traditional systems of water harvesting.
18. (a) Draw a neat labelled diagram of a germinated seed and label radicle, plumule and cotyledon .
(b) Mention function of each of these parts.
19. Name the organism Mendel used for his experiment. Explain about F1 and F2 progeny obtained by Mendel when he cross-bred the tall and the short varieties of the organism he experimented with.
20. What is meant by analogous organs and homologous organs ?
Identify the analogous and homologous organs amongst the following : Wings of a butterfly, wings of a bat, forelimbs of frog, forelimbs of a human.
21. How is sex of a new born determined genetically in human beings ?
22. (a) Specify the location of human testis in male reproductive system and write the advantage of it being present over there.
(b) Mention two roles of testis in reproductory system.
(c) Write two glands found in male reproductive pathway and specify their roles.
23. (a) Draw a neat diagram of human female reproductive system and label :
(i) Oviduct (ii) Ovary (iii) Uterus (iv) Cervix
(b) Mention the function of Uterus and Oviduct.

CLASS X:IMPORTANT QUESTIONS: PHYSICS

1. State the colour of sunlight scattered by air molecules in the atmosphere.
2. List four characteristics of images formed by plane mirrors.
3. What is dispersion ? What happens when light is passed through a glass prism.
4. What is meant by near point and far point of an eye ? State their values for the normal human eye.
5. State the reason of using convex mirrors as rear-view mirrors. A convex mirror used on an automobile has a focal length of 3 m. If a car behind is at a distance of 5 m, find the location of image of the car in the mirror.
6. Define power of a lens and state its SI unit. Which type of lens has a negative power ? Find the power of a lens of focal length +20 cm.
7. A person cannot see nearby objects clearly. State the defect of vision he is suffering from. Draw ray diagrams to show the defect and correction. Name the lens used for correction.
8. A concave lens of focal length 20 cm forms an image 10 cm away from the lens. Use lens formula to find the position of the object with respect to the lens. Also draw ray diagram to illustrate the image formed in this case.
9. (a) State the laws of refraction of light.
(b) Using the lens formula and sign conventions for refraction by spherical lenses find the position nature and magnification of the image formed by a convex lens of focal length 20 cm when object is placed at a distance of 18 cm from the lens.
10. A person suffering from an eye-defect uses lenses of power - 1D .Name the defect he is suffering from and the nature of lens used.
11. What is minimum number of rays required for locating the image formed by a concave mirror for an object? Draw a ray diagram to show the formation of a virtual image by a concave mirror.
12. An old person is unable to see clearly nearby object as well as distant objects.
(i) What defect of vision is he suffering from?
(ii) What kind of lens will be required to see clearly the nearby as well as distant objects? Give reasons?
13.(a) What is dispersion of light ?
(b) Name the :
(i) component of white light that deviates the least,
(ii) component of white light that deviates the most, while passing through a glass prism.
14. (a) Two lenses have power of i) +2 D ii) -4D.
What is the nature and focal length of each lens
(b) An object is kept at a distance of 100cm for lens of power-4D. Calculate image distance.
15. (a) A concave mirror produces three times enlarged image of an object placed at 10cm. in front of it. Calculate the focal length of the mirror.
(b) Show the formation of the image with the help of a ray diagram when object is placed 6 cm away from the pole of a convex mirror.
16. (a) The refractive index of diamond is 2.42. What is the meaning of this statement?
(b) What is the difference between virtual images produced by concave, plane and convex mirrors ?
(c) What does the negative sign in the value of magnification produced by a mirror indicates about a image ?
17. (a) Write one use of concave mirror as well as convex mirror.
(b) Draw ray diagrams for the following cases when a ray of light :
  (i) passing through centre of curvature of a concave mirror is incident on it.
  (ii) parallel to principal axis is incident on convex mirror
  (iii) is incident at the pole of a convex mirror
  (iv) passing through focus of a concave mirror incident on it.

CLASS X:IMPORTANT QUESTIONS: CHEMISTRY

SCIENCE QUESTION BANK :

CHEMISTRY

1. Write the two succeeding members of the following homologous series : C₂H₆, C₃H₈.
2. How does the atomic radii of elements change in periodic table :
   (a) down the group
   (b) across the period from left to right
3. State modern periodic table law. What is the number of total periods and groups in periodic table.
4. Explain why it is difficult to wash clothes with soap when water is hard. How do detergents help in overcoming this problem ?
5. Part of the periodic table is given below where atomic numbers of elements are given in the parenthesis.
   Li (3) Be (4) Na (11) Mg (12)
   K (19) Ca (20) Rb (37) Sr (38)
   (I) Give the electronic configuration of K.
   (ii) Predict the number of valance electrons in the atom of Ca.
   (iii) What is the number of shells in the atom of Na ?
   (iv) Arrange Be, Mg, Ca, Sr in the increasing order of the size of their respective atoms.
   (v) Predict whether Rb is a metal or non metal.
   (vi) Out of Na, Li, Be and Mg which one has biggest atom in size ?
6. (i) Explain the two characteristic features that are seen only in carbon and not in any other
   element, to form a large number of compounds.
   (ii) Write the names of the next homologue of CH₃ CH₂ OH and HCOOH.
7. A compound X is used in cough syrups and many tonics. It is also soluble in water in all proportions.
   (i) Name the compound X. Write its chemical formula.
   (ii) Which gas is evolved when the compound X reacts with sodium ? How will you test the presence of this gas ? Write the chemical equation involved in reaction of X with sodium.
8. Mention any two trends exhibited by elements when we go from left to right across the period of periodic table.
9. “Elements in Periodic Table show periodicity of properties” List any four such properties.
10. Write the name of the next homologue of CH₃OH and HCOOH.
11. How does boiling point and melting point of hydrocarbons change with increase in molecular mass ?
12. (a) Define homologous series of organic compounds. Mention any two characteristics of homologous series. (b) Describe a chemical test to distinguish between ethanol and Ethanoic acid. (c) Identify functional group in Pentanone.

Stay tuned for important questions of Physics and Biology.

For any queries, please comment....

Important questions for class ix

CHEMISTRY

1. State the postulate of Dalton’s Atomic theory that explains Law of Conservation of

Mass.

2. (a) Define the atomic mass unit.

(b) Write the chemical formulae of :

(i) Ammonium Carbonate (ii) Sodium Oxide

(c) Write the name of the compound Al2(SO4)3 and mention the ions present in it.

3. State the features of Rutherford’s atomic model.

4. If an element ‘X’ is available in the form of say, two isotopes ⁷⁹₃₅Br(49.7%) and ⁸¹₃₅Br(50.3%), calculate the average atomic mass of the atom of ‘X’.

5. (a) Define (i) Molar mass (ii) Avogadro constant

(b) What is the mass of 0.5 mole of NH3 ? Given Atomic mass of N = 14u, Atomic

mass of H = 1u.

(c) Calculate the number of particles in 31 g of P4 molecules. Atomic mass of

P=31u. (No 6.0221023 per mole)

(d) Find the number of moles in 87g of K2SO4 (Atomic mass of K=39u, S=32u,

O=16u)

6. (a) Define (i) Formula unit mass (ii) Polyatomic ion.

(b) Calculate the number of moles for the following.

(i) 36g of He (At. Mass of He 4 u) (ii) 12.04410²³ molecules of H₂O (At.mass of He1 u, O16 u)

(c) How many atoms are present in -

(i) SO₄^2- ion ? (ii) NH₄⁺ion ?

PHYSICS

1. State Archimedes’ principle. Based on this principle, write any one application.

2. List two conditions which need to be satisfied for the work to be done on an object ?

3. (a) School bags are provided with broad straps. Give reason.

(b) The relative density of iron is 7.8. What will be the mass of an iron brick with

dimensions 5 cm  10 cm  20 cm ? (Density of water is 1 g/cc)

4. Define 1 watt of power. A lamp consumes 1000 J of electrical energy in 10s. Calculate

its power.

5. How much work should be done on an object of 120 kg to increase its speed from 25

m/s to 40 m/s ?

6. A radio station is transmitting its signals at a frequency 400 Mhz. If the velocity of radio waves is 3*10⁸ m/s, Calculate the wavelength of radio waves.

7. (i) A light and a heavy object have the same momentum. What is the ratio of their kinetic energies ? Which one has a larger kinetic energy ?

(ii) A ball is dropped from a height of 10m. If the energy of the ball reduces by

40% after striking the ground, how much high can the ball bounce back ?

(g = 10ms^-2)

8. (i) State the law of conservation of energy.

(ii) Show that the energy of a freely falling body is conserved.

9. ‘Sound wave is a longitudinal wave and requires a material medium to propagate’.

Justify this statement with the help of an experiment.

10. What is an echo? What should be the minimum distance of the obstacle from the source of sound to hear an echo. An echo returned in 2 seconds. What is the distance

of the reflecting surface from the source, given that the speed of sound is 340 m/s.

BIOLOGY

1. Write the name of the group of plants which produces seeds but not fruits.

2. List any two human activities that you think would lead to air pollution.

3. State two reasons why whales are not grouped with fishes ?

4. List four ways of spreading communicable diseases.

5. On what basis are plants and animals put into different categories? Write points.

6. Write one point of difference each, between the following :

(a) Amphibians and Reptiles

(b) Aves and Mammals

(c) Gymnosperm and angiosperm

7. Write one point of difference each, between the following :

(a) Amphibians and Reptiles

(b) Aves and Mammals

(c) Gymnosperm and angiosperm

8. State two causes and two effects of depletion of ozone layer in the atmosphere.

9. (a) What is meant by acid rain? How has it affected the environment and historical monuments ?

(b) What is smog ? Name two diseases caused by smog.

10. (a) State two characteristic features of Bryophytes.

(b) Identify the class to which the following belong :-

(i) Cold blooded animals with scaly skin and two chambered heart.

(ii) Egg laying warm blooded animals with four chambered heart.

(iii) Cold blooded animals with scales and laying eggs near water.

11. (a) What are diploblastic and triploblastic animals ?

(b) How are breathing organs of fish and lizard different ?

(c) What is notochord ?

12. (a) Name two processes that remove O2 from the atmosphere and a process that

adds O2 to the atmosphere.

(b) Draw a schematic diagram to show how O2 is cycled in the atmosphere.

13. What is a Biogeochemical cycle ? List and explain the four steps of N cycle in nature.