Science Quiz Olympaid Selection Test Preparation

2024-2025
Q1: Which of the following is a base quantity in the SI system?
a) Energy

b) Length

c) Velocity

d) Area

Answer: b) Length
Explanation: Length is a fundamental base quantity in the SI system,
whereas energy, velocity, and area are derived quantities.

Q2: If an object moves with a constant speed in a circle, what is true

about its velocity?
a) Constant

b) Zero

c) Changes direction continuously

d) Remains positive

Answer: c) Changes direction continuously

Explanation: Velocity involves both magnitude and direction. In circular
motion, the direction changes continuously even if the speed is constant.

Q3: According to Newton’s second law, force is proportional to:

a) Distance

b) Acceleration

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c) Mass squared

d) Velocity

Answer: b) Acceleration
Explanation: Newton’s second law states that \( F = ma \), meaning force is
directly proportional to acceleration.

Q4: What is the SI unit of pressure?

a) N/m

b) Pa

c) J/s

d) N/kg

Answer: b) Pa
Explanation: Pressure is measured in Pascals (Pa), where \(1 \, \text{Pa} = 1
\, \text{N/m}^2\).

Q5: Which of the following is a unit of energy?

a) Watt

b) Joule

c) Coulomb

d) Pascal

Answer: b) Joule
Explanation: Energy is measured in Joules (J), and 1 Joule = 1 Newton-
meter.

Q6: What term describes the maximum force a material can withstand
without breaking?

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a) Elastic limit

b) Breaking point

c) Stress limit

d) Ultimate tensile strength

Answer: d) Ultimate tensile strength

Explanation: Ultimate tensile strength refers to the maximum stress a
material can endure before it breaks.

Q7: What happens to the wavelength of a wave as it enters a denser

medium?
a) Increases

b) Decreases

c) Remains the same

d) Depends on amplitude

Answer: b) Decreases
Explanation: When a wave enters a denser medium, its speed decreases, and
so does its wavelength.

Q8: What occurs when two waves meet in phase?

a) Destructive interference

b) Constructive interference

c) Refraction

d) Diffraction

Answer: b) Constructive interference

Explanation: When two waves meet in phase, their amplitudes add up,

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resulting in constructive interference.

Q9: Which of the following is a conductor?

a) Plastic

b) Rubber

c) Copper

d) Wood

Answer: c) Copper
Explanation: Copper is a good conductor of electricity due to the presence
of free electrons.

Q10: What is the potential difference across a 10-ohm resistor carrying

a current of 2 A?
a) 5 V

b) 10 V

c) 20 V

d) 50 V

Answer: c) 20 V
Explanation: By Ohm’s Law, \( V = IR = 2 \times 10 = 20 \, V \).

Q11: Which particle is found outside the nucleus?

a) Proton

b) Neutron

c) Electron

d) Alpha particle

Answer: c) Electron

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Explanation: Electrons orbit the nucleus in shells.

Q12: What is the molar mass of water (H₂O)?

a) 10 g/mol

b) 16 g/mol

c) 18 g/mol

d) 20 g/mol

Answer: c) 18 g/mol
Explanation: \( H_2O \) has 2 Hydrogen atoms (2 × 1) + 1 Oxygen atom
(16), totaling 18 g/mol.

Q13: Which bond type involves sharing of electrons?

a) Ionic

b) Metallic

c) Covalent

d) Hydrogen

Answer: c) Covalent
Explanation: In covalent bonding, atoms share electrons to achieve a full
outer shell.

Q14: An exothermic reaction:

a) Absorbs heat

b) Releases heat

c) Has no heat exchange

d) Converts heat to work

Answer: b) Releases heat

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Explanation: Exothermic reactions release heat into the surroundings.

Q15: What happens to the mass of a cathode during electrolysis?

a) Increases

b) Decreases

c) Remains the same

d) Changes unpredictably

Answer: a) Increases
Explanation: At the cathode, reduction occurs, and metal ions gain electrons
to form solid metal.

Q16: Which group contains the halogens?

a) Group 1

b) Group 2

c) Group 17

d) Group 18

Answer: c) Group 17
Explanation: Halogens are located in Group 17 and include elements like
chlorine and iodine.

Q17: What effect does increasing temperature have on the rate of a

reaction?
a) No effect

b) Slows it down

c) Speeds it up

d) Stops it

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Answer: c) Speeds it up
Explanation: Higher temperatures increase particle movement, leading to
more collisions and a faster reaction rate.

Q18: What structure controls the movement of substances into and out
of a cell?
a) Nucleus

b) Cytoplasm

c) Cell membrane

d) Cell wall

Answer: c) Cell membrane

Explanation: The cell membrane regulates what enters and exits the cell.

Q19: Which factor does NOT affect enzyme activity?

a) Temperature

b) pH

c) Enzyme concentration

d) Light intensity

Answer: d) Light intensity

Explanation: Light intensity does not affect enzyme activity; temperature
and pH are more relevant factors.

Q20: Which process moves water through the plant?

a) Osmosis

b) Transpiration

c) Active transport

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d) Photosynthesis

Answer: b) Transpiration
Explanation: Transpiration involves the movement of water from roots to
leaves, driven by evaporation.

Here are the remaining 30 MCQs with answers and explanations.

Q21: What is the main function of ribosomes?

a) Store genetic material

b) Produce energy

c) Synthesize proteins

d) Transport nutrients

Answer: c) Synthesize proteins

Explanation: Ribosomes are responsible for protein synthesis by translating
mRNA into polypeptides.

Q22: Which enzyme breaks down starch into maltose?

a) Lipase

b) Amylase

c) Protease

d) Catalase

Answer: b) Amylase
Explanation: Amylase is an enzyme that catalyzes the breakdown of starch
into maltose.

Q23: What kind of molecule is glucose?

a) Protein

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b) Lipid

c) Carbohydrate

d) Nucleic acid

Answer: c) Carbohydrate
Explanation: Glucose is a simple sugar and a carbohydrate that provides
energy to cells.

Q24: During which phase of the cell cycle does DNA replication occur?
a) G1 phase

b) G2 phase

c) S phase

d) M phase

Answer: c) S phase
Explanation: DNA replication occurs during the S (synthesis) phase of the
cell cycle.

Q25: Which nucleic acid carries the genetic code from DNA to
ribosomes?
a) tRNA

b) rRNA

c) mRNA

d) ATP

Answer: c) mRNA
Explanation: mRNA (messenger RNA) carries genetic information from
DNA to ribosomes for protein synthesis.

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Q26: In plants, which tissue transports water?
a) Phloem

b) Xylem

c) Epidermis

d) Cambium

Answer: b) Xylem
Explanation: Xylem transports water and minerals from roots to other parts
of the plant.

Q27: What pigment in red blood cells binds with oxygen?

a) Hemoglobin

b) Chlorophyll

c) Myoglobin

d) Carotene

Answer: a) Hemoglobin
Explanation: Hemoglobin in red blood cells binds to oxygen, enabling its
transport throughout the body.

Q28: Which organ is responsible for gas exchange in humans?

a) Heart

b) Liver

c) Lungs

d) Kidney

Answer: c) Lungs
Explanation: The lungs facilitate gas exchange, absorbing oxygen and

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releasing carbon dioxide.

Q29: What is the basic unit of all living organisms?

a) Atom

b) Molecule

c) Cell

d) Tissue

Answer: c) Cell
Explanation: Cells are the basic structural and functional units of all living
organisms.

Q30: Which disease is caused by Plasmodium species?

a) Tuberculosis

b) Malaria

c) Cholera

d) Dengue

Answer: b) Malaria
Explanation: Malaria is caused by Plasmodium parasites transmitted by
Anopheles mosquitoes.

Q31: What is the monomer of proteins?

a) Nucleotides

b) Fatty acids

c) Amino acids

d) Monosaccharides

Answer: c) Amino acids

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Explanation: Proteins are composed of amino acids linked together by
peptide bonds.

Q32: Which force acts against motion?

a) Gravitational force

b) Friction

c) Centripetal force

d) Electrostatic force

Answer: b) Friction
Explanation: Friction is a force that opposes the motion of objects in
contact.

Q33: What does the pH scale measure?

a) Light intensity

b) Temperature

c) Hydrogen ion concentration

d) Salinity

Answer: c) Hydrogen ion concentration

Explanation: The pH scale measures the acidity or alkalinity of a solution
based on hydrogen ion concentration.

Q34: Which gas is released during photosynthesis?

a) Carbon dioxide

b) Nitrogen

c) Oxygen

d) Methane

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Answer: c) Oxygen
Explanation: During photosynthesis, plants release oxygen as a byproduct.

Q35: What is the primary energy source for cellular processes?

a) DNA

b) RNA

c) ATP

d) NADPH

Answer: c) ATP
Explanation: ATP (adenosine triphosphate) provides energy for cellular
activities.

Q36: Which state of matter has no fixed shape but a definite volume?
a) Solid

b) Liquid

c) Gas

d) Plasma

Answer: b) Liquid
Explanation: Liquids have a definite volume but take the shape of their
container.

Q37: Which element is essential for the formation of bones and teeth?
a) Sodium

b) Calcium

c) Potassium

d) Iron

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Answer: b) Calcium
Explanation: Calcium is necessary for the development and maintenance of
bones and teeth.

Q38: What is the chemical formula of methane?

a) CO₂

b) CH₄

c) H₂O

d) NH₃

Answer: b) CH₄
Explanation: Methane consists of one carbon atom bonded to four hydrogen
atoms.

Q39: Which substance speeds up chemical reactions in biological

systems?
a) Enzyme

b) Substrate

c) Hormone

d) Antibody

Answer: a) Enzyme
Explanation: Enzymes act as biological catalysts that speed up chemical
reactions.

Q40: What is the charge on an electron?

a) +1

b) -1

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c) +2

d) 0

Answer: b) -1
Explanation: Electrons carry a negative charge of -1.

Q41: What type of wave is sound?

a) Transverse

b) Longitudinal

c) Electromagnetic

d) Stationary

Answer: b) Longitudinal
Explanation: Sound waves are longitudinal, with particles vibrating parallel
to the direction of wave propagation.

Q42: What type of bond forms between sodium and chlorine in sodium
chloride?
a) Covalent

b) Ionic

c) Metallic

d) Hydrogen

Answer: b) Ionic
Explanation: Sodium and chlorine form an ionic bond by transferring
electrons.

Q43: Which organelle is responsible for cellular respiration?

a) Ribosome

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b) Mitochondrion

c) Golgi apparatus

d) Nucleus

Answer: b) Mitochondrion
Explanation: The mitochondrion is the powerhouse of the cell, where
respiration takes place.

Q44: Which group of elements is known as noble gases?

a) Group 1

b) Group 17

c) Group 18

d) Group 2

Answer: c) Group 18
Explanation: Noble gases are found in Group 18 and are known for being
chemically inert.

Q45: What is the SI unit of electric current?

a) Volt

b) Ampere

c) Ohm

d) Watt

Answer: b) Ampere
Explanation: Electric current is measured in amperes (A).

Q46: Which molecule stores genetic information?

a) RNA

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b) DNA

c) Protein

d) Lipid

Answer: b) DNA
Explanation: DNA (deoxyribonucleic acid) stores the genetic information of
an organism.

Q47: What is the process of cell division in which identical daughter

cells are formed?
a) Meiosis

b) Mitosis

c) Binary fission

d) Budding

Answer: b) Mitosis
Explanation: Mitosis results in two identical daughter cells from a single
parent cell.

Q48: Which element is most abundant in the Earth's crust?

a) Oxygen

b) Hydrogen

c) Iron

d) Silicon

Answer: a) Oxygen
Explanation: Oxygen is the most abundant element in the Earth's crust by
weight.

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Q49: Which particle has no electric charge?
a) Proton

b) Electron

c) Neutron

d) Positron

Answer: c) Neutron
Explanation: Neutrons are neutral particles with no electric charge.

Q50: What is the process by which plants make food using sunlight?
a) Respiration

b) Transpiration

c) Photosynthesis

d) Fermentation

Answer: c) Photosynthesis
Explanation: Photosynthesis is the process by which plants use sunlight,
water, and carbon dioxide to produce glucose and oxygen.

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