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Science M.C.Q

MODEL PAPER 3 · CBSE STD 10 (CBSE - English Medium). 20 questions.

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M.C.Q

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20 questions · timed · auto-graded

MCQ 11 Mark
Assertion (A): CFCs deplete the ozone layer.
Reason (R): CFCs are used as refrigerants and in fire extinguishers.
  • ✓
    Both A and R are true and R is the correct explanation of A
  • B
    Both A and R are true but R is not the correct explanation of A
  • C
    A is true but R is false.
  • D
    A is false but R is true.
Answer
Correct option: A.
Both A and R are true and R is the correct explanation of A
(a) Both A and R are true and R is the correct explanation of A.
Explanation: The ozone layer is getting depleted at the higher levels of the atmosphere due to the effect of chlorofluorocarbons (CFCs) which are used as refrigerants and in fire extinguishers.
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MCQ 21 Mark
Assertion (A): The strength of the magnetic field produced at the centre of a current-carrying circular coil
increases on increasing the number of turns of the circular coil.
Reason (R): Magnetic field strength is directly proportional to the number of turns of the circular coil.
  • ✓
    Both A and R are true and R is the correct explanation of A
  • B
    Both A and R are true but R is not the correct explanation of A
  • C
    A is true but R is false.
  • D
    A is false but R is true.
Answer
Correct option: A.
Both A and R are true and R is the correct explanation of A
(a) Both A and R are true and R is the correct explanation of A.
Explanation: Both A and R are true and R is the correct explanation of A.
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MCQ 31 Mark
Assertion (A): XX chromosome give rise to female child whereas XY give rise to male child.
Reason (R): The Y chromosome in males is small than X chromosome.
  • A
    Both A and R are true and R is the correct explanation of A
  • ✓
    Both A and R are true but R is not the correct explanation of A
  • C
    A is true but R is false.
  • D
    A is false but R is true.
Answer
Correct option: B.
Both A and R are true but R is not the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A.
Explanation: Smaller Y chromosome, does not decide the gender of the child. Its presence is important not the size. Thus both assertion and reason are true, but reason is not the correct explanation of the assertion.
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MCQ 41 Mark
Assertion (A): In the following chemical equation,
$CuO ( s )+ Zn ( s ) \rightarrow ZnO ( s )+ Cu ( s )$
Zinc is getting oxidised and copper oxide is getting reduced.
Reason (R): The process in which oxygen is added to a substance is called oxidation whereas the process in which oxygen is removed from a substance is called reduction.
  • ✓
    Both A and R are true and R is the correct explanation of A
  • B
    Both A and R are true but R is not the correct explanation of A
  • C
    A is true but R is false.
  • D
    A is false but R is true.
Answer
Correct option: A.
Both A and R are true and R is the correct explanation of A
(a) Both A and R are true and R is the correct explanation of A.
Explanation: Both A and R are true and R is the correct explanation of A.
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MCQ 51 Mark
In the following groups of materials, which group (s) contains only non-biodegradable items?
i. Wood, paper, leather
ii. Polythene, detergent, PVC
iii. Plastic, detergent, grass
iv. Plastic, bakelite, DDT
  • A
    (iv)
  • ✓
    (ii) and (iv)
  • C
    (i) and (iii)
  • D
    (iii)
Answer
Correct option: B.
(ii) and (iv)
(b) (ii) and (iv)
Explanation: Group (i) has wood and leather which are biodegradable. Group (iii) has grass that is biodegradable hence the answer is (ii) and (iv) in which the given materials in the options cannot be degraded by micro-organisms and hence are non- biodegradable.
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MCQ 61 Mark
Refer to the given pie chart regarding contribution of different greenhouse gases and select the incorrect statement regarding it.
Image
  • ✓
    S is used in aerosol cans, jet fuel, air conditioners and refrigerators.
  • B
    Q is also produced by incomplete decomposition mostly by anaerobic methanogens.
  • C
    R are synthetic gaseous compounds of carbon and halogen
  • D
    Excessive use of fossil fuel is adding more P to atmosphere.
Answer
Correct option: A.
S is used in aerosol cans, jet fuel, air conditioners and refrigerators.
(a) S is used in aerosol cans, jet fuel, air conditioners and refrigerators
Explanation: In the given pie chart, P. Q. R and S are $CO _2, CH _4, CFCs$ and $N _2 O$ respectively. Chlorofluorocarbons(R) are used in aerosol. cans, jet fuel, air conditioners and refrigerators.
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MCQ 71 Mark
The resistance of the conductor is $R.$ If the length is doubled by stretching the wire, then its new resistance willbet be:
  • A
    $R$
  • ✓
    $4R$
  • C
    $8R$
  • D
    $2R$
Answer
Correct option: B.
$4R$
The resistance of a uniform metallic conductor is directly proportional to its length $(1)$ and inversely proportional to the area of its cross$-$section $(A).$
$R=\rho \frac{1}{A}$ where p is a constant of proportionality and is called the electrical resistivity of the material of the conductor.
$R _1=p \frac{l_1}{A_1}$ and $R _2=\frac{l_2}{A_2}$ and $l _2=2 l _1$
The volume of the wire remains unchanged.
$\therefore \pi r_1^2 l_1=\pi r_2^2 l_2$
$\Rightarrow\left(\pi r_1^2\right)\left(l_1\right)=\left(\pi r_2^2\right)\left(l_2\right)$
$\Rightarrow\left(A_1\right)\left(l_1\right)=\left(A_2\right)\left(2 \times l_1\right)$
$\Rightarrow A_2=\frac{A_1}{2}$
The volume of the wire remains unchanged.
$\therefore R _2=\rho \frac{l_2}{A_2}$
$\Rightarrow R _2=\rho \frac{2 \times 2 \times l_1}{A_1}$
$\Rightarrow R_2=4 \times R_1$
Thus, the new resistance becomes four times of the original resistance.
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MCQ 81 Mark
Which rule determines the direction of flow of current in the conductor?
  • A
    Fleming's left hand rule
  • ✓
    Fleming's right hand rule
  • C
    Maxwell's right hand grip rule
  • D
    Left hand thumb rule
Answer
Correct option: B.
Fleming's right hand rule
(b) Fleming's right hand rule
Explanation: The direction of induced current in a straight conductor is given by Fleming's right-hand rule.
It states that if we stretch the thumb, forefinger and the middle finger of the right hand at right angles to one another in such a way that the forefinger points in the direction of the magnetic field. Then, thumb gives the direction of motion of conductor (force), forefinger indicates the direction of magnetic field, and the middle finger points the direction of induced current.
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MCQ 91 Mark
In which part of the alimentary canal food is finally digested?
  • A
    Stomach
  • B
    Mouth cavity
  • ✓
    Small intestine
  • D
    Large intestine
Answer
Correct option: C.
Small intestine
(c) Small intestine
Explanation: Although the primary digestion process is conducted in the mouth and stomach. Most of the digestion process occurs in the small intestine and in large intestine digestion process will not take place.
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MCQ 101 Mark
Who is called the father of genetics?
  • A
    Stanley and miller
  • ✓
    Gregor Mendel
  • C
    Lamarck
  • D
    Darwin
Answer
Correct option: B.
Gregor Mendel
(b) Gregor Mendel
Explanation: Gregor Mendel is called the father of genetics because he was the first person in the world to observe the fact that characteristics were passed on from the parents to the children.
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MCQ 111 Mark
………… is a product of meiosis.
  • A
    Microspore mother cell
  • ✓
    Megaspore
  • C
    Primary endosperm nucleus
  • D
    Megaspore mother cell
Answer
Correct option: B.
Megaspore
(b) Megaspore
Explanation: Megaspore is a haploid cell that is formed by meiosis in the megaspore mother cell. It is the first cell of female gametophyte.
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MCQ 121 Mark
In an experiment with pea plants, a pure tall plant $(IT)$ is crossed with a pure short plant $(tt)$. The ratio of pure tall plant to pure short plants in $F_2$ generation will be
  • A
    $1:3$
  • B
    $3:1$
  • C
    $2:1$
  • ✓
    $1:1$
Answer
Correct option: D.
$1:1$
A cross between $(TT)$ and $(tt)$ would produce progenies with following genotypes$-$ In $F_2$ generation selfing of $ F_1$ progeny
$\text{Gametes} Tt$ $T$ $t$
$T$ $TT$ $Ti$
$t$ $Tr$ $t$
Pure tall $(TT),$ Mixed tall $(Tt)$ and Short $(tt)$. The ratio of pure tall and pure short plant is $1: 1.$
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MCQ 131 Mark
The energy-rich compound produced through respiration is
  • A
    ADP
  • B
    Pyruvic acid
  • C
    AMP
  • ✓
    ATP
Answer
Correct option: D.
ATP
(d) ATP
Explanation: In cellular respiration, an organism oxidizes glucose (i.e., combines it with oxygen) so as to form the energy-rich compound known as Adenosine Triphosphate (ATP). ATP, critical to metabolism (the breakdown of nutrients to provide energy or form new material), is the compound used by cells to carry out most of their ordinary functions. Among those functions are the production of new cell parts and chemicals, the movement of compounds through cells and the body as a whole, and growth.
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MCQ 141 Mark
Which one of the following is not in a liquid state at $10^\circ C$?
  • A
    $H _2 O$
  • B
    Glacial acetic acid
  • ✓
    $C _2 H _5 OH$
  • D
    Acetone
Answer
Correct option: C.
$C _2 H _5 OH$
The freezing point of pure ethanoic acid is $16.6^\circ C\  (61.9^\circ F)$. The freezing point of pure water is $0^\circ C.$ The freezing point of pure ethyl alcohol $(C_2H_5OH)$ is -$114.1^\circ C.$ The freezing point of pure acetone is $-95^\circ C.$ When ethanoic acid
$($acetic acid$)$ is cooled below $10^\circ C,$ it freezes to form a colourless, ice$-$like solid. The solid looks like a glacier and hence pure
ethanoic acid are called glacial ethanoic acid $($or glacial acetic acid$)$.
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MCQ 151 Mark
Alloys are homogeneous mixtures of a metal with a metal or nonmetal. Which among the following alloys contain non-metal as one of its constituents?
  • A
    Brass
  • ✓
    Steel
  • C
    Amalgam
  • D
    Bronze
Answer
Correct option: B.
Steel
(b) Steel
Explanation: Steel is an alloy of metal iron and non metal carbon which makes it widely used in making utensils, pipes, conduits and various other purposes.
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MCQ 161 Mark
An iron nail is suspended in $\ce{CuSO_4}$ solution and kept for a while. The solution:
Image
  • A
    Turns green and no coating will be formed on the nail.
  • ✓
    Turns green and a coating will be formed on the nail
  • C
    Remains blue and a coating is found on the nail
  • D
    Remain blue and no coating will be formed on the nail.
Answer
Correct option: B.
Turns green and a coating will be formed on the nail
The solution will turn green due to the formation of iron sulphate. A coating of copper is formed on the nail. Iron is more reactive than copper and displaces it from its solution.
$\ce{CuSO_4(aq) + Fe(s)} \rightarrow \ce{FeSO_4(aq) + Cu(s)}$
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MCQ 171 Mark
Two compounds $X$ and $Y$ have the same molecular formula$, C_3H_6O_2.$ Identify the functional groups and structural formulae of $X$ and $Y$
  • A
    $-CHO$ and $- CO , X = CH _3 CH _2 CHO , Y =CH _3 COCH _3$
  • B
    $-CO$ and $- COOH , X = CH _3 COCH _3, Y =$ $CH _3 CH _2 COOH$
  • C
    $-CHO$ and $- COOH , X = CH _3 CH _2 CHO , Y =$ $CH _3 CH _2 COOH$
  • D
    $-COOH$ and $- COOR , X = CH _3 CH _2 COOH$, $Y = CH _3 COOCH _3$ Empty
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MCQ 181 Mark
Match column 1 with column II and mark the correct option from the given codes.
Column IColumn II
(a) $Na _2 CO _3$(i) Used for disinfecting water.
(b) $Na _2 CO _3$(ii) Used for soda-acid fire extinguishers.
(c) $CaOCl _2$(iii) Used for removing permanent hardness of water.
(d) $CaSO _4 \cdot \frac{1}{2} H _2 O$(iv) Used for making toys, materials for decoration.
  • A
    (a) (ii), (b) - (iii), (c) - (i), (d) - (iv)
  • B
    (a) (iii), (b) - (ii), (c) - (i), (d) - (iv)
  • C
    (a) (i), (b) - (ii), (c) - (iv), (d) - (iii)
  • D
    (a) (iii), (b) - (i), (c) - (iv), (d) - (ii)
Answer
(a) (a)(ii), )(a)(ii), (b)(iii), (c) (i), (d) - (iv)
Explanation: (a)(ii), (b) (iii), (c) - (i), (d) - (iv)
Column IColumn II
(a) $Na _2 CO _3$(i) Used for disinfecting water.
(b) $Na _2 CO _3$(ii) Used for soda-acid fire extinguishers.
(c) $CaOCl _2$(iii) Used for removing permanent hardness of water.
(d) $CaSO _4 \cdot \frac{1}{2} H _2 O$(iv) Used for making toys, materials for decoration.
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MCQ 191 Mark
In the reaction$: CuO + H_2 \rightarrow Cu + H_2O_1$ the reducing agent is:
  • A
    $H _2 O$
  • ✓
    $H _2$
  • C
    $CuO$
  • D
    $Cu$
Answer
Correct option: B.
$H _2$
$CuO + H _2 \rightarrow Cu + H _2 O$
Compounds or elements which can cause reduction are called reducing agents.
A reducing agent is a substance that gives Hydrogen.
So$, H_2$ is a reducing agent.
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MCQ 201 Mark
Zinc pieces were placed in each of the four test tubes containing different salt solutions as shown below
Image
A colour change would be observed in solutions:
  • A
    $II$ and $IV$
  • ✓
    $III$ and $IV$
  • C
    $II$ and $III$
  • D
    $I$ and $IV$
Answer
Correct option: B.
$III$ and $IV$
The colour change will take place in $III$ and $IV$ as zinc is more reactive than iron as well as copper.
$\ce{Zn + \underset {PuleGreen}{ FeSO _4} \rightarrow \underset{Colorlean}{ ZnSO _4}+ Fe}$
$\ce{Zn + \underset{Cue}{ CuSO _4} \rightarrow \underset{Colorles:}{ ZnSO _4}+ Cu}$
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M.C.Q - Science STD 10 Questions - Vidyadip