MCQ Questions for Class 10 science with Answers PDF Download

MCQ Questions for Class 10 science with Answers PDF Download

Hey, welcome to mcqclass10.com .In this post you will get MCQ Questions for Class 10 science with answers pdf for term 1 2021 board exam.

MCQ Questions for Class 10 science

Q. 1) In the reaction PbS + 2H2O2 → PbSO4 + 4H2O, select the option that correctly identifies substance oxidized and substance reduced.


(a) PbS is oxidized and H2O is reduced

(b) PbSO4 is oxidized and H2O2 is reduced

(c) PbS is oxidized and H2O2 is reduced

(d) PbSO4 is reduced and H2O2 is oxidized

Answer : (c) PbS is oxidized and H2O2 is reduced


Explanation: Lead sulphide is oxidized to lead
sulphate as there is addition of oxygen atom
and Hydrogen peroxide is reduced to water as
it loses oxygen atom.

Q. 2) Hydrogen is placed along with Alkali metals in the modern periodic table though it shows non-metallic character

(a) as Hydrogen has one electron & readily loses electron to form negative ion.

(b) as Hydrogen can easily lose one electron like alkali metals to form positive ion.

(c) as Hydrogen can gain one electron easily like Halogens to form negative ion.

(d) as Hydrogen shows the properties of
non-metals.

Answer : (b) As Hydrogen can easily lose one electron like alkali metals to form positive ion

MCQ Questions for Class 10 science with answers pdf

Q. 3) Which of the following equations correctly represents the physical states of reactants and products?


(a) 2FeSO4(aq) → Fe2O3(aq) + SO2(g) + SO3(g)

(b) 2FeSO4(s) → Fe2O3(s) + SO2(g) + SO3(g)

(c) 2FeSO4(s) → Fe2O3(aq) + SO2(g) + SO3(g)

(d) 2FeSO4(aq) → Fe2O3(s) + SO2(g) + SO3(g)

Answer: (b) 2FeSO4(s) → Fe2O3(s) + SO2(g) + SO3(g)


Explanation: When crystals of ferrous sulphate (solid) are heated, it decomposes to ferric oxide (Fe2O3), sulphur dioxide (SO2) and sulphur trioxide (SO3). Ferric oxide is a solid, while SO2 and SO3 are gases.

Q. 4) During reaction of which metals with cold water, hydrogen gas catches fire?

(I) Sodium

(II) Calcium

(III) Magnesium

(IV) Potassium

(a) Both (I) and (II)

(b) Both (III) and (IV)

(c) Both (I) and (IV)

(d) Both (II) and (IV)

Answer: (c) Both (I) and (IV)


Explanation: Reaction of both sodium and
potassium with cold water is so violent and
exothermic that the hydrogen gas evolved
catches fire. Reaction of calcium with cold
water is less violent whereas magnesium does
not react with cold water but reacts with hot
water.
2K(s) + 2H2O(l) → 2KOH(aq) + H2(g) +
heat energy
2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g) +
heat energy

MCQ Questions for Class 10 science with answers pdf download

Q. 5) The effect of gas formed by heating sulphur powder on litmus paper is:


(a) It turns both dry blue litmus paper and moist blue litmus paper red.

(b) It turns dry blue litmus paper red but has no effect on moist blue litmus paper.

(c) It has no effect on dry blue litmus paper but turns moist blue litmus paper red.

(d) It has no effect on both dry blue litmus paper and moist blue litmus paper.

Answer: (c) It has no effect on dry blue litmus paper but turns moist blue litmus paper red.


Explanation: When sulphur powder is heated, it forms sulphur dioxide gas, which is acidic in nature. However, it shows acidic behaviour only in presence of water. Therefore, it has no effect on dry blue litmus paper, but turns moist blue litmus paper red.

Q. 6) Which of the following metals form an
amphoteric oxide?


(a) Al (b) Na
(c) Cu (d) Ca

Answer: (a) Al

MCQ Questions for Class 10 science pdf download


Explanation: Aluminium form amphoteric
oxides, which have both acidic and basic
characteristics.
Al2O3 + 6HCl → 2AlCl3 + 3H2O
(acid)
Al2O3 + 2NaOH → 2NaAlO2 + H2O
(base) (Sodium
aluminate)

Q. 7) Fungi are:


(a) Heterotrophic (b) Autotrophic
(c) Saprophytic (d) Parasitic

Answer: (c) Saprophytic


Explanation: Fungi feed on dead and decaying
matter. They release chemicals to break
complex organic matter into simple forms and
absorb them. This is called saprophytic mode
of nutrition


Q. 8) In humans, there are …………. pairs of salivary glands.


(a) Two (b) Three
(c) Six (d) Four

Answer: (b) Three


Explanation: There are three pairs of salivary
glands present in humans, namely the parotid
glands, submandibular and sublingual glands.

MCQ Questions for Class 10 science chemistry chapter 1


Q. 9) Which pancreatic enzyme helps in digesting proteins?


(a) Pepsin (b) Trypsin
(c) Chylomicrons (d) Both (a) and (b)

Answer: (b) Trypsin


Explanation: Trypsin is the pancreatic enzyme
which is effective in digesting proteins.


Caution
 Pepsin is a gastric enzyme and trypsin is a intestinal
enzyme, both responsible for the digestion of
proteins.


Q. 10) Why are arteries thick walled?


(a) They are under low pressure

(b) So that blood does not excude from the  vessels

(c) They are under high pressure

(d) Both (b) and (c)

Answer: (c) They are under high pressure


Explanation: Blood flows with pressure in
arteries so as to withstand the pressure
therefore, arteries are thick walled.

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MCQ Questions for Class 10 science with answers pdf term 1 exam


Q. 11) Name the cartilaginous flap which closes the opening of wind pipe durings swallowing:


(a) Glottis (b) Epiglottis
(c) Gullet (d) Epivalve

Answer: (b) Epiglottis


Explanation: The epiglottis is flap of cartilage
located in the throat behind the tongue and in
front of the larynx. The function of epiglottis is
to cover the mouth of trachea (or wind pipe)
when we swallow food so that the food may
not enter the trachea.

Q. 12) The power of a lens of focal length 20 cm in diopter is:


(a) 0.25 D (b) 2.0 D
(c) 5.0 D (d) 0.05 D

Answer: (c) 5.0 D


Explanation: P = 100
20 = 5.0 D

MCQ Questions for Class 10 science biology


Q.13) If the magnification of a lens has a positive value, the image formed is:


(a) inverted
(b) real and inverted
(c) real
(d) Virtual and erect

Answer: (d) virtual and erect


Explanation: If magnification is positive, then
image will always be virtual and erect. If
magnification is negative, then image will be
real and inverted.


Q. 14) An object is placed 40 cm from the concave mirror with a focal length of 20 cm. The image formed is:


(a) behind the mirror
(b) between the mirror and focus
(c) at focus
(d) centre of curvature of mirror

Answer: (d) centre of curvature of mirror


Explanation: Given focal length of concave
mirror, f = – 20 cm
Distance of object from concave mirror,
r = – 40 cm

MCQ Questions for Class 10 science life process

Q. 15) Velocity of light in air is 3 × 108 m/s and its velocity in a medium X is 1.0 × 108 m/s. Then, refractive index of medium X is:


(a) 3 (b) 5
(c) 0.5 (d) 2

Answer: (a) 3


Explanation: Refractive index of medium with
respect to air,
anm = Speed of light in air
Speed of light in medium
anm = 3 10
1 0 10
8
8
×
. × = 3


Q. 16) Which of the following phenomenons of light are involved in the formation of
ranibow?


(a) Reflection, refraction and dispersion

(b) Refraction, dispersion and total internal  reflection

(c) Refraction, dispersion and internal 
reflection 

(d) Dispersion, scattering and total internal  reflection

Answer: (b) Refraction, dispersion, total internal reflection


Explanation: During the formation of rainbow
phenomenon of dispersion refraction and total
internal reflection takes place.

MCQ Questions for Class 10 science chemistry pdf


Q. 17) At the traffic signals, red light is used for stop due to the reason that it can be seen
from a distance. This phenomenon is known
as:


(a) Refraction
(b) Diffraction
(c) scattering
(d) Total internal reflection

Answer: (c) Scattering


Explanation: The phenomena involved here
is scattering. When size of scatterer is much
smaller than wavelength of light then

Q. 18) Calcium phosphate is present in tooth
enamel. What happen when we consume
sweets?


(a) We suffer from diabetes
(b) Dissolution of enamel
(c) No effect on teeth is observed
(d) Teeth become weak from roots

Answer: . (b) Dissolution of enamel


Explanation: Calcium phosphate is a basic salt,
as it is a salt of weak acid (phosphoric acid)
and slightly stronger base (calcium hydroxide).
Thus, when pH of our mouth falls below
5.5 due to eating of sweets etc. i.e., mouth is
acidic the dissolution of tooth enamel (calcium
phosphate) starts which shows that calcium
phosphate is basic is nature.

MCQ Questions for Class 10 science chemistry chapter 1


Q. 19) Which of the following show a chemical reaction?


(a) MgSO4 + Fe (b) ZnSO4 + Fe
(c) CaSO4 + Pb (d) CuSO4 + Fe

Answer: (d)CuSO4 + Fe


Explanation: According to activity series, Ca >
Mg > Zn > Fe > Pb > Cu. Thus, Fe can displace
Cu from FeSO4


Q. 20) Which of the following metals melt when kept on your palm?


(I) Sodium                  (II) Mercury
(III) Caesium               (IV)Gallium

(a) (I) and (III)             (b) (II) and (IV)
(c) (III) and (IV)           (d) (II) and (III)

Answer: (c) (III) and (IV)


Explanation: Gallium and cesium have very
low melting points. They melt from the heat of
the palms.

Q. 21) Which of the following can be used as an acid–base indicator by a visually impaired student?


(I) Red cabbage lead extract
(II) Turmeric
(III) Vanilla essence
(IV)Onion extract


(a) Both (I) and (II) (b) Both (II) and (III)
(c) Both (III) and (IV) (d) (I), (III) and (IV)

Answer: (c) Both (III) and (IV)


Explanation: Olfactory indicators are the
substances whose odour or smell changes in
acidic or basic medium. These can therefore
be used by visually impaired persons to identify acids and bases. Examples of olfactory
indicators are vanilla essence and onion
extract.


Q. 22) Which acids are present in oranges and spinach?


(a) Citric acid in both
(b) Oxalic acid in both
(c) Oxalic acid and citric acid respectively
(d) Citric acid and oxalic acid respectively

Answer: (d) Citric acid and oxalic acid respectively


Explanation: Orange contains citric acid and
spinach contains oxalic acid. Both are organic
acids.

Q. 23) To obtain an image of magnification (–3), an object should be in which position in case of concave mirror?


(a) Between F and 2 F
(b) At F
(c) Between F and C
(d) Beyond 2 F

Answer: (c) Between F and C


Explanation: For m = – 3, the image is real,
inverted and enlarged. The object must be
placed between F and C of the concave mirror.


Q. 24) Why the sun appears white at noon?


(a) scattering is reduced if the distance to be  travelled in air is increased.

(b) scattering is increased if the distance to  be travelled in air is reduced.

(c) scattering is reduced if the distance to be  travelled in air is reduced.

(d) the sun is overhead at noon

Answer: (c) scattering is reduced if the distance to be travelled in air is reduced.


Explanation: At noon, the sun appear white
because light from the sun travel relatively
shorter distance in atmosphere and therefore
is least scattered.


Q. 25) Which colour suffers least deviation on passing through a prism?


(a) Blue
(b) Red
(c) White
(d) Violet

Answer: (b) Red


Explanation: On passing through a prism red
colour deviates the least while the violet colour
deviates the most.

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