Class 10th science 5 marks questions asked in previous year question paper

Class 10th science 5 marks questions (2010 to 2018) :

2010

Question 1. Write the name and symbols of two most reactive metals belonging to group I of the periodic
table. Explain by drawing electronic structure how either one of the two metals reacts with a halogen. With
which name is the bond formed between these elements known and what is the class of the compound so
formed known? State any four physical properties of such compounds.
.                                       OR
What is meant by refining of metals? Name the most widely used method of refining impure metals
produced by various reduction processes. Describe with the help of a labeled diagram how this method may
be used for refining of copper.

Question 2. Derive the expression for the heat produced due to a current ‘I’ flowing for a time interval ‘t’
through a resistor ‘R’ having a potential difference ‘V’ across its ends. With which name is the relation known? How much heat will an instrument of 12 W produce in one minute if it is connected to a battery of
12 V?
                                       OR
Explain with the help of a labeled circuit diagram how you will find the resistance of a combination of three
resistors, of resistance R1, R2 and R3 joined in parallel. Also mention how you will connect the ammeter and
the voltmeter in the circuit when measuring the current in the circuit and the potential difference across one
of the three resistors of the combination.

2011

Question 1. With the help of suitable diagrams, explain the various steps of budding in Hydra.
OR
What is binary fission in organisms? With the help of suitable diagrams, describe the mode of reproduction
in Amoeba.

Question 2. (a) State two properties of carbon which lead to a very large number of carbon compounds.
(b) Why does micelle formation take place when soap is added to water? Why are micelles not formed when
soap is added to ethanol?
OR
Explain isomerism. State any four characteristics of isomers. Draw the structures of possible isomers of
butane, C4H10.

Question 3. (a) What is meant by ‘power of a lens’?
(b) State and define the S.I. unit of power of a lens.
(c) A convex lens of focal length 25 cm and a concave lens of focal length 10 cm are placed in close contact
with each other. Calculate the lens power of this combination.
OR
(a) Draw a ray diagram to show the formation of image of an object placed between infinity and the optical
centre of a concave lens.
(b) A concave lens of focal length 15 cm forms an image 10 cm from the lens. Calculate
i. The distance of the object from the lens.
ii. The magnification for the image formed
iii. The nature of the image formed.

2012

Question 1. List the sign conventions for reflection of light by spherical mirrors. Draw a diagram and
apply these conventions in the determination of focal length of a spherical mirror which forms a three times
magnified real image of an object placed 16 cm in front of it.
OR
State the law of refraction of light which defines the refractive index of a medium with respect to the other.
Express it mathematically. How is refractive index of any medium 'A' with respect to a medium 'B' related to
the speed of propagation of light in two media A and B? State the name of this constant when one medium is
vacuum or air. The refractive indices of glass and water with respect to vacuum are 3/2 and 4/3 respectively.
If the speed of light in glass is 2 × 108 m/s, find the speed of light in
i. vacuum
ii. water

Question 2. What is the difference between the chemical composition of soaps and detergents?
State in brief the soaps in removing an oily spot from a shirt. Why soaps are not considered suitable for
washing when water is hard?
OR
List in tabular form three physical and two chemical properties on the basis of which ethanol and ethanoic
acid can be differentiated.

Question 3. Define the terms pollination and fertilisation. Draw a diagram of a pistil showing pollen tube
growth into the ovule and label the following: pollen grain, male gamete, female gamete and ovary.
OR
Describe in brief the role of
i. testis
ii. seminal vesicle
iii. vas deferens
iv. ureter
v. prostate gland in human male reproductive system.

2013

Question 1. (a) Write the function of placenta in females.
(b) List four ways of preventing pregnancy. State two advantages of using such preventive methods.

Question 2. (a) Identify A, B and C in the given diagram and write their functions.
(b) Mention the role of gamete and zygote in sexually reproducing organisms.

Question 3. (a) A person cannot read newspaper placed nearer than 50 cm from his eyes. Name the defect
of vision he is suffering from. Draw a ray diagram to illustrate this defect. List its two possible causes. Draw
a ray diagram to show how this defect may be corrected using a lens of appropriate focal length.
(b) We see advertisements for eye donation on television or in newspaper. Write the importance of such
advertisements.

Question 4. State Snell's law of refraction of light. Write an expression to relate refractive index of a
medium with speed to light in vacuum.
The refractive index of a medium 'a' with respect to medium 'b' is 2/3 and the refractive index of medium 'b'
with respect to medium 'c' is 4/3. Find the refractive index of medium 'c' with respect to medium 'a'.

Question 5. (a) Define the term 'isomers'
(b) Draw two possible isomers of the compound with molecular formula C3H6O and write their names.
(c) Give the electron dot structures of the above two compounds.

2014

Question 1. List two reasons for carbon forming a large number of compounds. Name the type of bonding
found in most of its compounds. Why does carbon form compounds mainly by this kind of bonding?
Give reason why the carbon compounds
(i) generally have low melting and boiling points.
(ii) do not conduct electricity in molten state.

Question 2. (a) List the parts of the human eye that control the amount of light entering into it. Explain
how they perform this function.
(b) Write the function of retina in human eye.
(c) Do you know that the corneal-impairment can be cured by replacing the defective cornea with the cornea
of the donated eye? How and why should we organise groups to motivate the community members to donate
their eyes after death?

Question 3. (a) Explain the following terms related to spherical lenses:
(i) optical centre
(ii) centres of curvature
(iii) principal axis
(iv) aperture
(v) principal focus
(vi) focal length
(b) A converging lens has focal length of 12 cm. Calculate at what distance the object should be placed from
the lens so that it forms an image at 48 cm on the other side of the lens.

Question 4. (a) Draw a sectional view of human female reproductive system and label the part where
(i) eggs develop.
(ii) fertilisation takes place.
(iii) fertilised egg gets implanted.
(b) Describe, in brief, the changes the uterus undergoes
(i) to receive the zygote.
(ii) if zygote is not formed.

Question 5. (a) Name the parts labelled as A, B, C and D in the diagram given below:

(b) What is pollination? State its significance.
(c) How does fertilisation occur in flowers? Name the parts of the flower that develop into (i) seed, and (ii)
fruit after fertilisation

2015

Question 1. What is meant by power of a lens? Define its SI unit.You have two lenses A and B of focal lengths
+10 cm and –10 cm, respectively. State the nature and power of each lens. Which of the two lenses will
form a virtual and magnified image of an object placed 8 cm from the lens? Draw a ray diagram to justify
your answer.

Question 2. One half of a convex lens of focal length 10 cm is covered with a black paper.
Can such a lens produce an image of a complete object placed at a distance of 30 cm from the lens?
Draw a ray diagram to justify your answer. A 4 cm tall object is placed perpendicular to its principal axis of
a convex lens of focal length 20 cm. The distance of the object from the lens is 15 cm. Find the nature,
position and the size of the image.

Question 3. How do Mendel’s experiments show that the
(a) traits may be dominant or recessive
(b) traits are inherited independently

Question 4.(a) Name the human male reproductive organ that produces sperms and also secretes a hormone. Write the
functions of the secreted hormone.
(b) Name the parts of the human female reproductive system where
i. fertilisation takes place
ii. Implantation of the fertilised egg occurs Explain how the embryo gets nourishment inside the mother’s
body.
Question 5. Both soap and detergent are some type of salts. What is the difference between them? Describe in brief
the cleansing action of soap. Why do soaps not form lather in hard water? List two problems that arise due
to the use of detergents instead of soaps.

2016

Question 1. It is desired to obtain an erect image of an object, using concave mirror of focal length of 12
cm.
(i) What should be the range of distance of an object placed in front of the mirror?
(ii) Will the image be smaller or larger than the object? Draw ray diagram to show the formation of image in
this case.
(iii) Where will the image of this object be, if it is placed 24 cm in front of the mirror? Draw ray diagram for
this situation also justify your answer.
Show the positions of pole, principal focus and the centre of curvature in the above ray diagrams.

Question 2. Define evolution. How does it occur? Describe how fossils provide us evidences in support of
evolution.

Question 3. What is placenta? Describe its structure. State its functions in case of a pregnant human
female.

Question 4. A carbon compound `P’ on heating with excess conc. H2SO4 forms another carbon compound
`Q’ which on addition of hydrogen in the presence of nickel catalyst forms a saturated carbon compound
`R’. One molecule of `R’ on combustion forms two molecules of carbon dioxide and three molecules of
water. Identify P, Q and R and write chemical equations for the reactions involved

Question 5. What is atmospheric refraction? Use this phenomenon to explain the following natural events:
(a) Twinkling of stars
(b) Advanced sunrise and delayed sunset.
Draw diagrams to illustrate your answers.

Question 6. (a) Define focal length of a divergent lens.
(b) A divergent lens of focal length 30 cm forms the image of an object of size 6 cm on the same side as the
object at a distance of 15 cm from its optical center. Use lens formula to determine the distance of the object
from the lens and the size of the image formed.
(c) Draw a ray diagram to show the formation of image in the above situation.

2017

Question 1. With the help of one example for each, distinguish between the acquired traits and the
inherited traits. Why are the traits/experiences acquired during the entire lifetime of an individual not
inherited in the next generation? Explain the reason of this fact with an example.

Question 2. (a) Write the functions of each of the following parts in a human female reproductive system:
(i) Ovary
(ii) Uterus
(iii) Fallopian tube
(b) Write the structure and functions of placenta in a human female.

Question 3. Why certain compounds are called hydrocarbons? Write the general formula for homologous
series of alkanes, alkenes and alkynes and also draw the structure of the first member of each series. Write
the name of the reaction that converts alkenes into alkanes and also write a chemical equation to show the
necessary conditions for the reaction to occur.

Question 4. (a) A student suffering from myopia is not able to see distinctly the object placed beyond 5 m.
List two possible reasons due to which this defect of vision may have arisen. With the help of ray diagrams
explain.
(i) Why the student is unable to see distinctly the objects placed beyond 5 cm from his eyes.
(ii) The type of the corrective lens used to restore proper vision and how this defect is corrected by the use
of this lens.
(b) If, in this case, the numerical value of the focal length of the corrective lens is 5 m, find the power of the
lens as per the new Cartesian sign convention

Question 4. Analyse the following observation table showing variation of image distance (v) with object
distance (u) in case of a convex lens and answer the questions that follow without doing any calculations:

(a) What is the focal length of the convex lens? Give reason to justify your answer.
(b) Write the serial number of the observation which is not correct. On what basis have you arrived at this
conclusion?
(c) Select an appropriate scale and draw a ray diagram for the observation at S. No. 2. Also find the
approximate value of magnification.

QueStion 5. (a) If the image formed by a mirror for all position of the object placed in front of it is always
diminished, erect and virtual, state the type of the mirror and also draw a ray diagram to justify your answer.
Write one use such mirrors are put to and why.
(b) Define the radius of curvature of spherical mirrors. Find the nature and focal length of a spherical mirror
whose radius of curvature is +24 cm.

2018

Question 1. (a) A student is unable to see clearly the words written on the black board placed at a distance of
approximately 3 m from him. Name the defect of vision the boy is suffering from. State the
possible causes of this defect and explain the method of correcting it.
(b) Why do stars twinkle ? Explain.
OR
(a) Write the function of each of the following parts of human eye :
(i) Cornea (ii) Iris (iii) Crystalline lens (iv) Ciliary muscles
(b) Why does the sun appear reddish early in the morning ? Will this phenomenon be observed by an
astronaut on the Moon ? Give reason to justify your answer.

Question 2. (a) The modern periodic table has been evolved through the early attempts of Dobereiner, Newland
and Mendeleev. List one advantage and one limitation of all the three attempts.
(b) Name the scientist who first of all showed that atomic number of an element is a more fundamental
property than its atomic mass.
(c) State Modern periodic law.

Question 3. (a) Mention any two components of blood.
(b) Trace the movement of oxygenated blood in the body.
(c) Write the function of valves present in between atria and ventricles.
(d) Write one structural difference between the composition of artery and veins.

Question 4. (a) Write the steps involved in the extraction of pure metals in the middle of the activity series from
their carbonate ores.
(b) How is copper extracted from its sulphide ore ? Explain the various steps supported by chemical
equations. Draw labelled diagram for the electrolytic refining of copper.

Question 5. (a) Write the function of following parts in human female reproductive system :
(i) Ovary (ii) Oviduct (iii) Uterus
(b) Describe in brief the structure and function of placenta.

Question 6. (a) State Fleming’s left hand rule.
(b) Write the principle of working of an electric motor.
(c) Explain the function of the following parts of an electric motor.
(i) Armature (ii) Brushes (iii) Split ring

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