Q. 1 ) Oxygen is transported by respiratory
(a) It is more soluble in water than CO2
(b) Haemoglobin has high affinity for it.
(c) It easily diffuses to all body parts
(d) It is easily absorbed by our tissues
Answer: (b) Haemoglobin has high affiinity for it.
Explanation: The respiratory pigment
heamoglobin has high affinity for oxygen and
therefore oxygen is transported in our body by
it. Carbon dioxide is more soluble in water than oxygen is and hence is mostlytransported in the dissolved form in our blood.
Q. 2) Which enzyme is secreted by the gastric glands?
(a) Amylase (b) Pepsin
(c) Trypsin (d) Lipase
Answer: (b) Pepsin
Explanation: The gastric glands present in the
wall of the stoma release hydrochloric acid, a
protein digesting enzyme called pepsin, and
Q. 3) Which of the following is not a requisite of any respiratory surface to become highly efficient are:
(a) Large surface area
(b) Thick walls
(c) Rich blood supply
(d) Fine and delicate surface area
Answer: . (b) Thick walls
Explanation: The respiratory surface must
have a large, fine and delicate surface area
to get enough oxygen, thin walls for easy
diffusion and exchange of respiratory gases
and rich blood supply for transport of gases.
Q. 4) .If a graph is plotted between sin r taken on X-axis and sin i taken on Y-axis, where i is
the angle of incidence and r is the angle of
refraction for a given pair of media, then:
(I) Graph will be a parabola
(II) Graph will be a straight line
(III) Slope of graph will give the refractive index of the second medium with respect to the first
(IV) Slope of graph will give the speed of light in the second medium.
(a) Both (I) and (III)
(b) Both (II) and (III)
(c) Both (I) and (IV)
(d) Both (II) and (IV)
Answer: (b) Both (II) and (III)
Explanation: According to Snell’s law, the
ratio of sin
r for a given pair of media is a
constant and is equal to the refractive index of
the second medium with respect to the first.
Q. 5) A real image 1/5
the size of the object is formed at a distance of 18 cm from a lens. From the table select the row containing the correct identification of lens and focal length of the lens.
Answer: (d) Type of tens : Convex Focal length : +15 cm
Explanation: It is given that the image formed
by the lens is a real image which is 1/5 times
the size of the object. A real image is formed
only by a convex lens as a concave lens always
forms a virtual and erect image
Q. 6) Harsh wants to see a magnified image while shaving in a mirror. What type of mirror should use:
(a) convex mirror
(b) concave mirror
(c) plane mirror
(d) combination of (a) and (b)
Answer: (b) concave mirror
Explanation: Harsh must use concave mirror
to get a magnified image.
Q. 7) It the image formed by a spherical mirror for all positions of the object placed in front of it always erect and diminished what type of mirror is it:
(a) convex mirror
(b) plane mirror
(c) concave mirror
(d) could be concave and convex
Answer: (a) convex mirror
Q. 8) The time difference between actual sunset and the apparent sunset is about:
(a) 2 min (b) 3 min
(c) 4 min (d) 5 min
Answer: (a) 2 min
Explanation: Due to atmospheric refraction,
the sun is visible two minutes after actual
Q. 9) What is the colour of sunlight scattered by the dust particles in the atmosphere:
(a) Blue (b) Red
(c) White (d) Violet
Answer: (c) White
Explanation: White colour of the sunlight
is scattered by the dust particles in the
Q. 10) Select the correct equation(s) which
represent double displacement reaction?
(I) Pb + CuCl2 → PbCl2 + Cu
(II) Na2SO4 + BaCl2 → BaSO4 + 2NaCl
(III) C + O2 → CO2
(IV)CH4 + 2O2 → CO2 + 2H2O
(a) (I) and (IV) (b) (II) only
(c) (I) and (II) (d) (III) and(IV)
Answer: (b) (II) only
Explanation: In double displacement reactions, one component each of both the reacting molecules is exchanged to form the products
Q. 11) Following metals are taken and each of them was tested for its reaction with cold
water, hot water and steam: Zn, Al, Cu, Fe, Mg, Na, K Select the correct observations:
(I) Na and K react violently with cold water.
(II) Mg does not react with cold water but reacts with hot water.
(III) Al, Zn and Cu react with steam
(IV) Fe does not react with water or steam at all.
(a) Both (I) and (II)
(b) Both (II) and (III)
(c) Both (I) and (IV)
(d) Both (III) and (IV)
Answer: (a) Both (I) and (II)
Explanation: Metals like K and Na react
violently with cold water.
2K(s) + 2H2O(l) → 2KOH(aq) + H2(g) + Heat
2Na(s)+ 2H2O(l)→2NaOH(aq) + H2(g) + Heat
Mg does not react with cold water but reacts
with hot water to form Mg(OH)2.
Metals like Al, Zn and Fe react with steam to
form a metal oxide.
2Al(s) + 3H2O(g) → Al2O3(s) + 3H2(g)
3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g)
Metals like Pb, Cu, Ag and Au do not react with
water at all.
Q. 12) When dilute hydrochloric acid is added to iron filling:
(a) Hydrogen gas and iron chloride are
(b) Chlorine gas and hydrogen gas evolved
(c) Iron salt and water produced
(d) No reaction takes place
Answer: (a) Hydrogen gas and iron chloride are produced
Explanation: When dilute hydrochloric acid is added to iron filling then hydrogen gas and iron chloride are produce.
6HCl + 2Fe 2FeCl3 + 3H2
Hydrochloric Iron filling Ironchloride Hydrogen acid
Q. 13) If a person is stung by a bee, it causes
burning pain and irritation.
Application of which of the following on the
stung area can give relief from the pain?
(a) Vinegar (b) Orange juice
(c) Baking soda (d) Tomato juice
Answer: (c) Baking soda
Explanation: Bee-sting leaves an acid which
causes pain and irritation. Therefore, applying
a mild base like baking soda on the stung area
gives relief. As vinegar, orange juice and tomato juice contain acid, they will not be helpful in the given situation.
Q. 14) What will be the minimum distance between an object and its real image formed by convex lens?
(a) f (b) >4f
(c) 2f (d) 4f
Answer: (d) 4f
Explanation: The minimum distance is 4f. i.e.
when an object is placed at one of the two
centres of curvature, and the image is formed
at the other centre of curvature, the the image
will be real.
Q. 15) Select the correct statements :
(I) Phloem transports soluble products of photosynthesis in plants.
(II) Xylem transports amino acids and other substances.
(III) Translocation of food and other
substances takes place in sieve tubes.
(IV)Translocation in phloem is achieved by utilizing energy.
(a) (I) and (II) (b) (II) and (III)
(c) (I), (II) and (III) (d) (I), (III) and(IV)
Answer:(d) (I), (III) and (IV)
Explanation : Statement II is incorrect as the
transport of amino acids and other substances
is done by phloem
Q. 16) Which of the following event will not take place if the saliva lacks in salivary amylase?
(a) Break down of starch to simple sugar
(b) Breakdown of proteins
(c) Break down of fats
(d) Creating an acidic medium
Answer: (a) Break down of starch to simple sugar
Explanation: Saliva contains salivary amylase
which breaks down starch into simple sugar
Q. 17) Focal length of a plane mirror is:
(a) – 25 (b) infinite
(c) zero (d) 25 cm
Answer: (b) infinite
Explanation: Focal length of a plane mirror
is infinite as the radius of curvature is infinite.
Q. 18) The power of the lens is – 1.0 D. What is the nature of this lens?
(a) Concave lens (b) Convex lens
(c) Both (d) Cannot be predicted
Answer: (a) concave lens
Explanation: Negative power is associated
with concave lens and convex mirror
Q. 19) For a convex mirror, parallel rays of light appear to:
(a) diverge (b) converge
(c) remains parallel (d) none of the above
Answer: (a) diverge
Explanation: Convex mirror is a diverging
mirror while concave mirror is a converging
Q. 20) A student tabulated the following
information based on his studies of optical
Select the row/s which contain correct
(a) Only (I) (b) Only (II)
(c) (I) and (III) (d) (II) and (IV)
Answer: (b) Only (II)
Explanation: Formation of rainbow is due to
dispersion of sunlight by the tiny droplets of
water present in the atmosphere. Twinkling of
stars and early sunrise are due to atmospheric
refraction whereas reddish colour of sun at
sunrise and sunset is due to the scattering of
Q. 21) Rajendra conducted an experiment using a concave mirror with a focal length of 30 cm. He places an object at a distance of 20 cm in front of the mirror. The image is formed
(a) 20 cm in front of the mirror
(b) 10 cm in front of the mirror
(c) 30 cm behind the mirror
(d) 60 cm behind the mirror
Answer: (d) 60 cm behind the mirror
Q. 22) compound Z is manufactured by the
action of a gas X, which is a product of Chlor
alkali process, on a substance Y in a plant as
Z is used as an oxidising agent in many
chemical industries and also used for
disinfecting drinking water.
Select the row containing the correct
identification of X, Y and Z from the table
Answer: (d) X : Chlorine gas; Y : Dry slaked lime; Z : Bleaching powder
Q. 23) Which of the compounds given in table above are ionic compounds?
(I) Magnesium oxide
(II) Sodium chloride
(a) Both (I) and (II)
(b) (I), (II) and (III)
(c) (I), (II) and (IV)
(d) Both (IV) and (III)
Answer: (c) (I), (II) and (IV)
Explanation: As the melting and boiling
points of ionic compounds is very high, we
can conclude from the given table that the
compounds Magnesium oxide, Sodium chloride and Cesium bromide are ionic compounds
Q. 24) The atomic number of four elements P, Q, R, S are 10, 12, 14 and 16 respectively. The two elements which can react to form ionic compounds are:
(a) P and S (b) Q and R
(c) P and R (d) Q and S
Answer: (d) Q and S
Explanation: The electronic configuration of
the given elements is given below:
P : 2, 8
Q : 2, 8, 2
R : 2, 8, 4
S : 2, 8, 6
Q is a metal (as it has 2 valence electrons) and
S is a non-metal (having 6 valence electrons),
they can react to form an ionic compound
Q. 25) Which of the following statement is true about ionic compounds?
(I) Ionic compounds are crystalline solids.
(II) Ionic compounds are soluble in solvents such as kerosene and petrol.
(III) Ionic compounds conduct electricity when dissolved in water.
(IV)Ionic compounds conduct electricity in the molten state.
(a) Both (I) and (II)
(b) Both I and (III)
(c) (I), (III) and (IV)
(d) (I), (II) and (IV)
Answer: (c) (I), (III) and (IV)
Explanation: Ionic compounds are generally
crystalline solids and hard due to the strong
force of attraction between the positive and negative ions. They are generally brittle.
These conduct electricity when dissolved in
water as its solution in water contains ions.
These conduct electricity in the molten state as
the electrostatic forces of attraction between
the oppositely charged ions are overcome due
to the heat. However, these do not conduct electricity in the solid state due to their rigid structure. Ionic compounds are soluble in polar solvents such as water and insoluble in solvents such as kerosene, petrol etc.