The general question often asked in NDA Examination :
1. A light bulb’s filament is made up of the following materials?
a) Platinum
b) Tantalum
c) Tungsten
d) Antimony
Answer: c)
2. Which of the colored lights below has the lowest frequency?
Sound waves are ____________ waves.
a) Pressure
b) Longitudinal
c) Electromagnetic
d) Mechanical
Answer: c)
Explanation: Sound waves are not Electromagnetic Waves.
3. Which of the following colored light has the lowest frequency?
a) Green
b) Blue
c) Red
d) Violet
Answer: c)
Explanation: Red color has the lowest frequency of visible light.
4. The artificial geostationary satellite’s period is?
a) 8 hours
b) 12 hours
c) 24 hours
d) 46 hours
Answer: c)
Explanation: The period of an artificial geostationary satellite is 24 hours.
5. The value of universal gravitational constant G is:
a) 9.8 m/s2
b) 6.673×10-11 N m2 kg-2
c) 6.371 x 106 m
d) 1.738 x 10 6 m
Answer: b)
Explanation: The value of the universal gravitational constant G is 6.673×10-11 N m2 kg-2
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6. What is the metric unit for weight magnitude?
a) Distance (meter)
b) Mass (grams)
c) Force (Newton)
d) None of the above
Answer: c)
Explanation: The unit of the magnitude of the weight is Newton (Force).
7. What is the value of Pi?
a) 3.14159
b) 3.14358
c) 3.14258
d) 3.14289
Answer: a)
Explanation: The value of Pi is approximately 3.14159. It is a mathematical constant and its symbol is π.
8. Which of the following is the finest conductor of electricity?
a) Copper
b) Aluminium
c) Iron
d) Silver
Answer: d)
Explanation: Although pure silver is the best conductor of electricity, other options are more common due to its scarcity. A material’s electrical conductivity is determined by how readily its atoms can offer free electrons for current flow. Any material with no free electrons in its atoms is incapable of conducting electricity.
9. Small liquid drops are spherical in shape because
a) of adhesion
b) of gravitational force
c) of the atmospheric pressure from all the sides on the top
d) the liquid tends to have the minimum surface area are due to surface tension
Answer: d)
Explanation: Surface tension causes the liquid to have the smallest possible surface area. Because its molecules are constantly stretched, a drop of liquid attempts to occupy the smallest surface area possible in a given volume. The spherical shape is used to obtain this smallest area. Surface tension is created by these cohesive forces, which means that a liquid’s upper surface is always tense.
10. Which of the following is related to the Chandrashekhar Limit?
a) Stars
b) Black holes
c) Both of these
d) None of these
Answer: a)
Explanation: It refers to the mass limit at which stars collapse. The maximum mass of a stable white dwarf star is known as the Chandrasekhar limit. It is the mass at which the star’s electron degeneracy pressure is insufficient to counteract its own gravitational attraction. As a result, white dwarfs with masses greater than this threshold would experience gravitational collapse, eventually transforming into a neutron star or black hole.
11. A Light Year is a measure of?
a) Light intensity
b) Time
c) Distance
d) None of the Above
Answer: c)
Explanation: A Light Year is known as the distance traveled by light in one year, which is equal to 3 lakh kilometers/sec × 24 hrs × 60 min × 60 seconds. This unit is used to measure astronomical distances between various celestial bodies like planets, stars, galaxies, etc.
12. Asteroid’s circles are between which two planets in the Solar System?
a) Venus and Mars
b) Mars and Earth
c) Mars and Jupiter
d) Jupiter and Saturn
Answer: c)
Explanation: The asteroids are minor planets, especially those in the inner Solar System. The term was earlier applied to any astronomical object orbiting the Sun, which did not show the disc of a planet and did not have comet-like properties. But in modern science, the term “asteroid” refers to the minor planets of the inner Solar System including those which are co-orbital with Jupiter.
13. Can you find the correctly matched pair
a) Madam Curie: X-ray
b) Albert Einstein: Photoelectric effect
c) Linus Pauling: Electron
d) C V Raman: Stark effect
Answer: b)
Explanation: Many languages refer to X-radiation as Rontgen radiation, after the German scientist Wilhelm Rontgen, who is typically credited with its discovery and who termed it X-radiation to denote an unknown sort of radiation. C V Raman got the Nobel Prize for his work on the Raman Effect. This discovery of the photo-electric equation earned Albert Einstein the Nobel Prize in Physics. Radioactivity – Madam Curie Electro negativity scale by Linus Pauling
14. The terms refraction, reflection, dispersion, and diffraction are all related to?
a) Light
b) Sound
c) Magnetism
d) None of the Above
Answer: a)
Explanation: In optics, refraction is a phenomenon that often occurs when waves travel from a medium with a given refractive index to a medium with another at an oblique angle. Reflection of light is either specular (mirror-like) or diffuse (retaining the energy, but losing the image) depending on the nature of the interface. Dispersion is the separation of white light into colors or of any radiation according to wavelength. Diffraction is the slight bending of light as it passes around the edge of an object.
15. In degrees Celsius, the minimum temperature beyond which matter cannot be cooled is:
a) 95.50
b) 100
c) 273.15
d) 473.50
Answer: c)
Explanation: The temperature at this point is known as absolute zero. Absolute zero is the lowest point on the thermodynamic temperature scale, a state in which the enthalpy and entropy of a cooled ideal gas are equal to zero. At least, in theory, all molecular motion should stop at this moment.
Practice UPSC NDA & NA Mathematics Mock Test with Answers (300 Marks)
16. Who among the following is credited with discovering the electromagnetic induction principles?
a) Michael Faraday
b) Volta
c) Coulomb
d) Gauss
Answer: a)
Explanation: Michael Faraday was an English scientist who made significant contributions to the fields of electrochemistry and electromagnetism. The principles underpinning electromagnetic induction, diamagnetism, and electrolysis were among his most important discoveries.
17. Which of the following statements regarding Pi is true?
a) It is the non-repeating decimal value
b) It is the nonterminating decimal value
c) It is repeating and terminating decimal value
d) It is a non-repeating, non-terminating decimal value
Answer: d)
Explanation: Pi is a non-repeating, non-terminating decimal value because it is irrational.
18. The quartz clock functions using Which approach?
a) Piezo-electric effect
b) Gauss effect
c) Relativistic effect
d) Mass defect
Answer: a)
Explanation: The principle of Piezoelectricity refers to the electrical charge, which accumulates in certain solids like crystals, ceramics, bone, DNA, and various proteins in response to mechanical stress. The word piezoelectricity means electricity resulting from pressure.
19. Who has estimated the circumference of the planet using Pi = 22/7 as a factor?
a) Archimedes
b) John Machin’s
c) Aryabhatta
d) None of the above
Answer: c)
Explanation: Aryabhatta calculated the circumference of the earth and used Pi= 22/7 as a constant in the calculation around the 5th century BC.
20. Applications for cryogenic engines include?
(a) sub-marine propulsion
(b) frost-free refrigerators
(c) rocket technology
(d) researches in superconductivity
Answer: (c)
