The National Defence Academy (NDA) and Combined Defence Services (CDS) exams are extremely competitive and require extensive preparation and knowledge in a variety of subjects, including science. We have compiled a list of the 100 most likely science questions that will appear in the upcoming NDA 1 CDS 1 2023 exams in this blog. These questions cover a wide range of subjects, including physics, chemistry, and biology. Our goal is to provide a comprehensive guide that will assist candidates in effectively preparing for the science section of the NDA CDS exams. So, let’s get started and investigate the top 100 science questions.

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So Below is the list of the 100 most expected Science Questions for NDA CDS 1 2023.

• Which element forms the Highest number of compounds?
• Carbon
• Nitrogen
• Argon
• Oxygen

• What is the Combined name of Water Gas + Producer Gas?
• Di-Water
• Semi-Water
• Hydro-Water
• Pro-Water

• What is the most reactive form of carbon?
• Charcoal
• Peat
• Lignite
• Bituminous

• What is the Hybridization of the C atom in a Diamond?
• Sp
• Sp2
• Sp3
• None of the above

• What is the Product of Calcination and Respiration?
• Carbon Dioxide
• Oxygen
• Nitrogen
• Argon

• Which one of the following is not an example of Thermoplastic?
• Teflon
• PVC
• Polyethylene
• Bakelite

• Elements were Discovered by
• Robert Boyle
• Antoine Lavoisier
• Joseph Proust
• Ritcher

• NH4Cl sublimes due to its
• Decomposition
• Composition
• Solubility
• Vapur

• What is Plasma?
• Super Excited particles when the matter is heated
• Super Excited particles when the matter is cooled
• Super Excited particles when the matter is frozen
• Super Excited particles when the matter is vaporized

• Osmosis is the process of
• movement of solvent particles from low conc to high conc
• movement of solvent particles from high conc to low conc
• movement of solute particles from low conc to high conc
• movement of solute particles from high conc to low conc

• Solubility depends on
• Nature of solute
• Nature of solvent
• Temperature
• All of the above

• Henry’s law relates to
• Pressure and Temprature
• Pressure and Solubility
• Pressure and Mass
• Pressure and Density

• Oxygen in the tank of Sea Divers is mixed with
• Nitrogen
• Argon
• Helium
• Gas

• Which is the Second most abundant element in the Earth’s Crust
• Aluminum
• Silicon
• Iron
• Phosphorus

• Which of the following glass can cut UV rays
• Crook
• Lead Crystal
• Flint
• Pyrex

• Sodium Silicate is Also known as
• Water Glass
• Pyrex glass
• Crook glass
• Flint glass

• Enriched uranium is
• Uranium rods are kept under the special shield
• Natural uranium in which the component of radioactive isotope U235 is artificial increased
• Natural uranium mixed with thorium
• Uranium rods coated with chromium

• Match List-I with List-II and select the correct answer from the codes given below:

	List-I	List-II
A.	Morphine	1. Antiseptic
B.	Sodium	2. Alloy
C.	Boric acid	3. Analgesic
D.	German silver	4. Kerosene oil

Codes:

	A	B	C	D
(a)	4	3	1	2
(b)	2	4	3	1
(c)	3	1	4	2
(d)	3	4	1	2

• The difference between a nuclear reactor and an atomic bomb is that
• no chain reaction takes place in a nuclear reactor while in the atomic bomb, there is a chain reaction.
• the chain reaction in a nuclear reactor is controlled.
• the chain reaction in a nuclear reactor is not controlled.
• no chain reaction takes place in an atomic bomb while it takes place in a nuclear reactor.

• The order of appearance of the following with increasing temperature during the refining of crude oil is     
• Kerosene, gasoline, diesel
• Diesel, gasoline, kerosene
• Gasoline, kerosene, diesel
• Gasoline, diesel, kerosene

• Consider the following statements: If there were no phenomenon of capillarity
• It would be difficult to use a kerosene lamp.
• One would not be able to use a straw to consume a soft drink.
• The blotting paper would fail to function.
• The big trees that we see around us would not have grown on the earth. Which of the statements given above is/are correct?
  • (a) 1, 2, and 3 only
  • (b) 1, 3, and 4 only
  • (c) 2 and 4 only
  • (d) 1, 2, 3 and 4

• The blue color of the water in the sea. What is the reason behind the phenomenon?
• Refraction of the blue light by the impurities in seawater.
• Scattering of blue light by water molecules.
• Refraction of blue sky by seawater.
• Absorption of other colors except for the blue color by water molecules.

• What is a “ Kiss of death”?
• A flower whose smell was the basis of a discovery on the smell that led to the award of the 2004 Nobel Prize in Medicine.
• A chemical whose discovery ultimately won the scientists the 2004 Nobel Prize in Chemistry.
• A good wine flavor working on which scientists won the 2004 Nobel Prize in Chemistry.
• A network in the brain associated with smell whose discovery led the scientists to win the 2004 Nobel Prize in Physiology and Medicine.

• A hydrogen bomb is based on the principle of
• controlled fusion reaction
• uncontrolled fusion reaction
• controlled fission reaction
• uncontrolled fission reaction

• Which of the following substances is/are ozone-depleting? Select the correct answer from the codes given below:
• Chlorofluorocarbons
• Halons
• Carbon tetrachlorideCodes:
  • 1 only
  • 1 and 2 only
  • 2 and 3 only
  • 1, 2 and 3

• Helium is preferred to hydrogen in air balloons because it
• is cheaper
• is less dense
• has greater lifting power
• does not form an explosive mixture with air

• Which one of the following pairs is correctly matched?
• Silver iodide — Horn silver
• Silver chloride — Artificial rain
• Zinc phosphide — Rat poison
• Zinc sulfide — Philosopher’s wool

• While tinning brass utensils, the ammonium chloride powder used to clean the hot utensil produces fumes of
• Ammonia
• Carbon monoxide
• Hydrochloric acid
• Ammonia and hydrochloric acid

• Hydrofluoric acid is not kept in glass bottles because it reacts with
• Visible light
• Sodium oxide of glass
• Aluminum oxide of glass
• Silicon dioxide in glass

• In the process of electroplating a utensil with zinc,
• The utensil is made of the cathode
• Pure zinc is made the anode
• The utensil is made the cathode and pure zinc is made the anode
• The utensil is made the anode and pure zinc is made the cathode

• Enriched uranium is
• Uranium rods are kept under the special shield
• Natural uranium in which the component of radioactive isotope U235 is artificial increased
• Natural uranium mixed with thorium
• Uranium rods coated with chromium

• The inexhaustible source of energy of the stars is due to
• Conversion of hydrogen to helium
• Conversion of helium to hydrogen
• Decay of radioactive elements
• Excess of oxygen that helps to burn and release energy

• When soggy biscuits are kept inside the fridge for some time they become crisp because
• Cooling releases extra moisture
• Humidity inside the fridge is low and extra moisture is absorbed
• Humidity inside the fridge is high and extra moisture is absorbed
• The pressure inside the fridge is high and helps in releasing extra moisture

• Which one of the following statements is not true about cosmic rays?
• They are electromagnetic waves
• They have a very short wavelength
• They are made of highly energetic charged particles
• They originated from the sun

• In cold weather, aquatic animals survive even when water to the top layer of the lake freezes into ice because
• They can breathe in ice
• They have enough accumulated oxygen inside them
• Their body structure is such that they can survive without oxygen.
• Water has the highest density of 4°C so underneath the top layer of ice there is a layer of water.

• Consider the following statements:
• Androecium and gynoecium are reproductive organs of flowers.
• Calyx and corolla are necessary for the female reproductive organs of a flower.
• Which of the statements given above is/are correct?
  • 1 only
  • 2 only
  • Both 1 and 2
  • Neither 1 nor 2

• The pulmonary vein is the only artery in which pure blood is circulated from the lungs to the heart.
• Deoxygenated blood is circulated in the arteries.
• Which of the above statements is/are correct?
  • (a) 1 only
  • (b) 3 only
  • (c) 1 and 2 only
  • (d) 1, 2 and 3

• Match List-I with List-II and select the correct answer from the codes given below: List-I List-II
• Father of circulatory 1. Stephen Hales system
• Father of plant 2. William Harvey physiology
• Coined the term 3. Karl Landsteiner ‘Genera’
• Discovered various 4. John Ray blood groups
  • Codes: A B C D
  • (a)1432
  • (b)2314
  • (c)2143
  • (d)4312

• Consider the following statements:
• Assertion (A): Arteries carry blood from various body organs to the heart.
• Reason (R): Veins carry blood from the heart to various body organs.
  • 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.
  • A is true, but R is false.
  • Both A and R are false.

• Consider the following statements:
• Femur is the smallest bone in the human body.
• Stapes is the longest bone in the human body.
• Enamel is the hardest part of the human body. Which of the statements given above is/are correct?
  • 1 and 2 only
  • 2 and 3 only
  • 3 only
  • All of the above

• Consider the following statements:
• The virus was discovered by Ivanovski.
• The bacteria were discovered by Rudolf Virchow.
• The cell theory was proposed by Schleiden and Schwann.
• Which of the statements given above is/are correct?
  • 1 and 2
  • 2 and 3
  • 1 and 3
  • 1, 2 and 3

• Match List-I with List-II and select the correct answer using the codes given below:
• List-I List-II
• (Sugar) (Source)
• Cellulose 1. Honey
• Fructose 2. Sugarcane
• Maltose 3. Cotton wool
• Sucrose 4. DisaccharideCodes
  • A B C D
  • 1 2 3 4
  • 3 1 4 2
  • 2 3 4 1
  • 4 1 2 3

• Match the following casual agents and the disease they cause in plants.
• List-I List-II
• Xanthomonas spp. 1. Bacterial leaf blight of rice
• Magnoporthe grisea 2. Citrus canker
• Phytophthora infestans 3. Blast of rice
• Xanthomonas 4. Blight of potatoaxonopodis or late blight
• Codes:
  • A B C D
  • 4 3 2 1
  • 1 3 4 2
  • 3 1 2 4
  • 1 4 2 3

• Consider the following statements and choose the correct ones.
• Flavr savr is a genetically modified tomato that remains fresh and flavourful for longer than a normal tomato.
• This GM tomato has blocked the enzyme polygalacturonase.
• This enzyme is responsible for cell wall formation.
  • (a) 1 only
  • (b) 2 only
  • (c) 1 and 2
  • (d) 1, 2 and 3

• Consider the following statements:
• Cambium is responsible for secondary growth.
• Cork is obtained from the apical meristem.
• The vascular cambium and cork cambium are examples of lateral meristem. Which of the statements given above is/are correct?
  • (a) 1 only
  • (b) 2 only
  • (c) 1 and 3
  • (d) 1, 2 and 3

• Consider the following statements and choose the correct ones.
• Hirudin, an anticoagulant protein, is obtained from Brassica napus.
• Pyrethrin is an insecticide obtained from the floral heads of Vinca rosea.
• The tissue culture technique is based on totipotency.
  • (a) 1 and 2 only
  • (b) 1 and 3 only
  • (c) 2 and 3 only
  • (d) All are correct

• Consider the following statements and choose the correct ones.
• Loose smut of wheat is caused by Puccinia graminis.
• The Father of Indian mycology and plant pathology is E.J. Butler.
  • (a) 1 only
  • (b) 2 only
  • (c) Both 1 and 2
  • (d) Neither 1 nor 2

• Which of the following is not a correct statement?
• Prophyra, laminaria, and sargassum are edible algae.
• Agar-agar is obtained from Gelidium andGracilaria.
• Algin is obtained from red algae, while carrageenin is from brown algae.
• Chlorella and Spirulina are unicellular algae rich in protein.

• Which of the following statements are correct about the functions of the blood?
• Transportation of oxygen.
• Transportation of hormones.
• Control of body temperature.
  • Excessive bleeding.Codes:
  • (a) 1 and 2 only
  • (b) 3 and 4 only
  • (c) 1, 2 and 3
  • (d) 1, 2, 3 and 4

• Consider the following statements:
• Assertion (A): All the proteins in our food are digested in the small intestine only.
• Reason (R): The protein-digesting enzymes from the pancreas are released into the small intestine. Codes:
  • 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.
  • A is true, but R is false.
  • A is false, but R is true

• Consider the following statements and select the correct answer from the codes given below:
  • In DNA, the base adenine, guanine, thymine, and cytosine are found.
  • The nucleus contains all the DNAs of a cell.
  • In RNA, thymine is replaced with uracil.
  • RNA is mainly found to be in the cytoplasm.
  • Codes:
  • (a) 1, 2 and 3
  • (b) 2 and 3 only
  • (c) 1 and 4 only
  • (d) 1, 2, 3 and 4

• With reference to the animal cell, which of the following statements is correct?
• There is no cell wall in animal cells but the cell is covered by a plasma membrane.
• Chlorophyll is not found in animal cells.
• Lysosome occurs in plant cells.
• Almost in all animal cells, centrioles exist.
  • Codes:
  • (a) 2 and 3 only
  • (b) 1, 2, and 3 only
  • (c) 1, 2 and 4
  • (d) All of the above

• Consider the following statements :
• In algae, the reproductive organs are single-celled
• Fern plants lack a true vascular system. Which of the statements given above is/are correct?
• (a) Only 1
• (b) Only 2
• (c) Both 1 and 2
• (d) Neither 1 nor 2

• Which of the following statements about sexual reproduction in flowering plants is correct?
• Stamen is present in the center of a flower.
• Stamen produces pollen grains in the ovary.
• The swollen bottom part of the carpel is the ovary.
• The fusion of germ cells gives rise to a zygote.
• Select the correct answer using the code given below.
  • (a) 2, 3, and 4 only
  • (b) 2 and 4 only
  • (c) 1 and 3 only
  • (d) 1, 2, 3, and 4 only

• Consider the following statements :
• Different plant species grow together.
• Light cannot penetrate into the lower strata full of undergrowth. Which of the following types of vegetation is characterized by the above?
  • Equatorial moist evergreen
  • Tropical deciduous
  • Mediterranean
  • Warm temperate broad-leaved deciduous
    
• With regard to animal breeding, which one among the following is not correct?
• In-breeding: Mating of more closely related animals within the same breed for 1 – 2 generations
• Out-breeding: Breeding of unrelated animals of the same breed without common ancestors for 4 – 6 generations
• Cross-breeding: Superior males of one breed are mated with superior females of another breed
• Out-crossing: Offspring is called an ‘out-cross’

• Consider the following statements regarding the recent global outbreak of ‘Swine flu
• The agent of infection is not well identified
• The risk is higher for those who consume pork
• It has the propensity to spread from contact with an infected person
• The absence of an effective treatment or vaccine makes it risky for a global pandemic
• Which of the statements given above is/are correct?
  • (a) I, II and IV
  • (b) III and IV
  • (c) II and III
  • (d) III and I

• A balanced diet should have approximately
• 1/5 protein, 3/5 fat and 1/5 carbohydrate
• 3/5 protein, 1/5 fat and 1/5 carbohydrate
• 1/5 protein, 1/5 fat and 3/5 carbohydrate
• 1/2 protein, 1/4 fat, and 1/4 carbohydrate 

• The following question consists of two statements, one labeled as the Assertion (A) and the other as ‘Reason (R), You are to examine these two statements carefully and select the answers to these items using the codes given below: 
• Assertion (A): Though carbohydrates are covalent compounds, they are soluble in water.
• Reason (R): Compounds that form hydrogen bonds with water are generally soluble in water.
  • Both A and R are individually true and R is the correct explanation of A
  • Both A and R are individually true but R is NOT the correct explanation of A
  • A is true but R is false
  • A is false but R is true

• With reference to human nutrition consider the following statements
• Banana is a richer source of carbohydrates than apples
• Banana contains some amount of protein also
• Spinach has no protein at all
• Potatoes are richer sources of protein than peas. Which of the above statements is correct?
  • 1 and 2
  • 2, 3 and 4
  • 1, 3 and 4
  • 1, 2, 3 and 4

• Cow milk is a rich source of
• Vitamin A
• Vitamin B
• Vitamin C
• Vitamin D

• The only snake that builds its nest is
• Krait
• King cobra
• Chain viper
• Saw scaled viper

• Consider the following statements :
• The heart is three-chambered in fishes
• The heart is four-chambered in birds
• All animals of class amphibia are characterized by two pairs of limbs
• In all reptiles, respiration is by lungs only Which of the above statements is correct?
  • 1, 2, 3 and 4
  • 1 and 3
  • Only 1
  • 2 and 4

• We are given three copper wires of different lengths and different areas of the cross-section. Which one of the following would have the highest resistivity?
• Copper wire of 50 cm length and 1 mm diameter
• Copper wire of 25 cm in length and 0.5 mm diameter
• Copper wire of 10 cm length and 2.0 mm diameter
• All the wires would have the same resistivity

• Which of the following statements about ‘fission’ is correct?
• It is related to the creation of new individuals by means of cell division in a unicellular organism.
• It is related to the transformation of heavier nuclei into smaller nuclei.
• It is related to the creation of heavier nuclei by means of combining two higher nuclei.
• Select the correct answer using the code given below:
  • (a) 1 only
  • (b) 2 only
  • (c) 1 and 2 only
  • (d) 1 and 3 only

• Which one of the following is an electric conductor?
• A plastic sheet
• Distilled water
• Human body
• A wooden thin sheet

• A non-spherical shining spoon can generally be considered as a
• Spherical mirror
• Parabolic mirror
• Plane mirror
• Lens

• Who amongst the following is a pioneer in discovering the heating effect of electric current?
• Isaac Newton
• Galileo Galilei
• James P. Joule
• J.J. Thomson

• Which one of the following laws of electromagnetism does not give the direction of the magnetic field?
• Right-hand thumb rule
• Fleming’s left-hand rule
• Fleming’s right-hand rule
• Faraday’s law of electromagnetic induction

• How many internal reflections of light take place in the formation of the primary rainbow?
• 0
• 1
• 2
• More than 2

• The direction of acceleration in uniform circular motion is along the
• direction of motion.
• tangent to the circle at the point of observation.
• the direction of velocity.
• the direction perpendicular to the velocity

• The weight of an object is due to
• The net force acting on it.
• The total of all forces acting on it irrespective of their directions.
• The force that it exerts on the ground.
• Its inert property.

• The size of particles being studied in ‘nano-technology’ is about
• 1Å–10 nm
• 1–100 nm
• 1–50 μ
• 1 mm–10 mm

• An object weighs 9N on the surface of the Earth. What would be its weight, when measured on the surface of a planet where the acceleration due to gravity is 9 times that on the surface of the Earth?
• The weight would remain the same
• The weight would be equal to 1N
• The weight would become 9 times
• The weight will be reduced to

• The twinkling of a star is due to:
• atmospheric reflection of Starlight
• atmospheric refraction of Starlight
• continuous change in the position of the star
• oscillation of Starlight

• A convex lens has a focal length of 15 cm. At what distance should an object be placed in front of the lens to get a real image of the same size as the object?
• 15 cm
• 10 cm
• 30 cm
• 40 cm

• Which one of the following statements about biogas is not correct?
• it is mainly composed of methane gas
• it is a nonrenewable source of energy
• it is formed by the decomposition of cow dung in the absence of oxygen
• it burns without smoke and leaves no residue

• If the magnification produced by a lens is +2 then the image is:
• erect, virtual, and smaller than the object
• inverted, real, and smaller than the object
• erect, virtual end larger than the object
• inverted, real, and larger than the object

• What is the correct sequence of resistivity of silver, nichrome, and glass at room temperature?
• Silver < Nichrome < Glass
• Glass < Nichrome < Silver
• Silver < Glass < Nichrome
• Nichrome < Silver < Glass

• At the time of short-circuit, the current in the circuit :
• reduces substantially
• does not change
• increases heavily
• keeps on fluctuating

• Which one of the following statements is not correct?
• an electric motor converts electrical energy into mechanical energy
• an electric generator works on the principle of electromagnetic induction
• the magnetic field at the center of a long circular coil carrying current will be parallel straight lines
• a wire with green insulation is usually the live wire of an electric supply

• A boy completes one round of a circular track of diameter 200 m in 30 s. What will be the displacement at the end of 3 minutes and 45 seconds?
• 50 m
• 100 m
• 200 m
• 236 m

• What happens to the gravitational force between two objects if the mass of one object is doubled and the distance between them is also doubled?
• The force would remain the same
• The force would be doubled
• The force would be halved
• The force would increase by a factor of 4

• A glass prism splits white light into different colors. This phenomenon is called the dispersion of light by a prism. Which one of the following statements is correct?
• The red light will deviate the most and it is because of the reflection of light
• Violet light will deviate the most and it is because of the refraction of light
• The red light will deviate the most and it is because of the refraction of light
• Violet light will deviate the most and it is because of the reflection of light

• Refraction of light, as it enters from one transparent medium to another, is due to
• change in temperature of the media
• change in the amplitude of light
• change in speed of light
• internal property of light

• A bus starting from a bus stand and moving with uniform acceleration attains a speed of 20 km/h in 10 minutes. What is its acceleration?
• 200 km/h²
• 120 km/h²
• 100 km/h²
• 240 km/h²

• The magnetic field lines inside a current carrying long solenoid are in the form of
• Ellipse
• Parabola
• Hyperbola
• Parallel straight lines

• A ray of light traveling from a rarer medium to a denser medium
• slows down and bends away from, the normal.
• slows down and bends towards the normal.
• speeds up and bends away from the normal.
• speeds up and bends towards the normal.

• An electric circuit is consisting of a cell, an ammeter, and a nichrome wire of length l. If the length of the wire is reduced to half (l/2), then the ammeter reading
• decreases to one half
• gets doubled
• decreases to one-third
• remains unchanged

• What is the effect of the pressure of a human body on sand?
• Larger while standing than while lying.
• Smaller while standing than while lying.
• Same while standing or lying.
• Larger while standing during the daytime and smaller during the night time while lying.

• What is the effect of the pressure of a human body on sand?
• Larger while standing than while lying.
• Smaller while standing than while lying.
• Same while standing or lying.
• Larger while standing during the daytime and smaller during the night time while lying.

• A sound wave has a frequency of 4 kHz and a wavelength of 30 cm. How long will it take to travel 2.4 km?
• 2.0 s
• 0.6 s
• 1.0 s
• 8.0 s

• An electric bulb is connected to a 110 V generator. The current is 0.2 A. What is the power of the bulb?
• 0.22 W
• 2.2 W
• 22 W
• 220 W

• The numerical ratio of displacement to the distance for a moving object is
• always less than 1
• always equal to 1
• always more than 1
• equal or less than 1

• A wave completes 24 cycles in 0.8 s. The frequency of the wave is
• 30 Hz
• 24 Hz
• 36 Hz
• 8 Hz

• The frequency of sound waves can be expressed in
• Second
• Cycle
• Metre per second
• Cycle per second

• A boat is set into vertical Vibration by waves of speed 5 ms-1 whose crests are 5m apart. The Time period of vertical vibration of the boat is
• 4 s
• 2 s
• 1 s
• 0.5 s

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Also read:

• 100 Most Expected Science Questions For NDA CDS 2023
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