TNPSC Group 2 / 2A - Light sound heat nuclear physics laser electronics and communications. Online Test (MCQ Quiz)

1. What is the unit of luminous intensity?

A) Lux B) Lumen C) Candela D) Joule

2. Which phenomenon explains why we see a rainbow after rain?

A) Reflection B) Refraction C) Dispersion D) Diffraction

3. What is the speed of light in a vacuum?

A) Approximately 3 x 10^8 meters per second B) Approximately 3 x 10^8 kilometers per hour C) Approximately 1.5 x 10^8 meters per second D) Approximately 1.5 x 10^8 kilometers per hour

4. Which type of mirror is used in a periscope?

A) Concave mirror B) Convex mirror C) Plane mirror D) Spherical mirror

5. What is the phenomenon of bending of light around obstacles called?

A) Interference B) Diffraction C) Polarization D) Scattering

6. Which gas is used in LASER systems for creating a coherent beam of light in some applications?

A) Helium B) Neon C) Argon D) Carbon Dioxide

7. What is the characteristic property of sound that distinguishes a loud sound from a soft sound?

A) Frequency B) Wavelength C) Amplitude D) Speed

8. What is the unit of sound intensity level?

A) Watt per square meter B) Decibel C) Hertz D) Pascal

9. Which of the following is a transverse wave?

A) Sound wave B) Light wave C) Water wave (surface) D) Both sound and water waves

10. What is the phenomenon of the change in frequency of a sound wave due to the relative motion between the source and the observer called?

A) Reflection B) Refraction C) Doppler Effect D) Diffraction

11. Which type of sound has a frequency above the human hearing range (typically > 20 kHz)?

A) Infrasound B) Audible sound C) Ultrasound D) Noise

12. What is the process by which heat is transferred through direct contact of particles?

A) Conduction B) Convection C) Radiation D) Advection

13. Which of the following is the best conductor of heat?

A) Wood B) Plastic C) Silver D) Air

14. What is the SI unit of temperature?

A) Celsius B) Fahrenheit C) Kelvin D) Rankine

15. What is the phenomenon of heat transfer through the movement of fluids (liquids or gases)?

A) Conduction B) Convection C) Radiation D) Diffusion

16. Which type of surface absorbs and emits thermal radiation most effectively?

A) Shiny and smooth B) Dull and rough C) Shiny and rough D) Dull and smooth

17. What is the term for the energy associated with the random motion of atoms and molecules in a substance?

A) Potential Energy B) Kinetic Energy C) Thermal Energy D) Chemical Energy

18. What is the process by which heat is transferred through electromagnetic waves?

A) Conduction B) Convection C) Radiation D) Absorption

19. What is the specific heat capacity of a substance?

A) The heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius. B) The heat required to raise the temperature of 1 kilogram of the substance by 1 Kelvin. C) The heat required to change the state of 1 gram of the substance without changing its temperature. D) The total thermal energy of a substance.

20. Which of the following is NOT a form of nuclear reaction?

A) Nuclear fission B) Nuclear fusion C) Radioactive decay D) Combustion

21. What is nuclear fission?

A) The process of combining two light nuclei to form a heavier nucleus. B) The splitting of a heavy nucleus into lighter nuclei, releasing energy. C) The spontaneous emission of radiation from an unstable nucleus. D) The absorption of a neutron by a nucleus to become unstable.

22. What is nuclear fusion?

A) The splitting of a heavy nucleus into lighter nuclei, releasing energy. B) The process of combining two light nuclei to form a heavier nucleus, releasing energy. C) The emission of alpha particles from a nucleus. D) The conversion of protons to neutrons within a nucleus.

23. What is the primary fuel for nuclear fusion in stars like our Sun?

A) Uranium B) Plutonium C) Hydrogen D) Carbon

24. What is radioactive decay?

A) The process of splitting a heavy nucleus. B) The process of combining light nuclei. C) The spontaneous transformation of an unstable atomic nucleus into a different nucleus, accompanied by the emission of radiation. D) The chain reaction of nuclear fissions.

25. What are the three main types of radioactive emissions?

A) Alpha, Beta, Gamma B) X-rays, Ultraviolet, Infrared C) Protons, Neutrons, Electrons D) Radio waves, Microwaves, Visible light

26. What is the half-life of a radioactive isotope?

A) The time it takes for all of the isotope to decay. B) The time it takes for half of the radioactive atoms in a sample to decay. C) The time it takes for a radioactive atom to emit one particle. D) The time it takes for a radioactive substance to become stable.

27. What is the main principle behind nuclear power plants?

A) Nuclear fusion B) Nuclear fission C) Radioactive decay D) Chemical combustion

28. What is the term for a chain reaction in nuclear fission where each fission event causes, on average, one more fission event?

A) Controlled reaction B) Uncontrolled reaction C) Sustained reaction D) Initiated reaction

29. What is a LASER?

A) Light Amplification by Stimulated Emission of Radiation B) Light Absorption by Scattered Emission of Radiation C) Loud Amplification by Sound Emission and Resonance D) Light Analysis by Spectral Emission and Reflection

30. Which property makes laser light distinct from ordinary light?

A) Polychromatic and divergent B) Monochromatic and coherent C) Incoherent and non-directional D) Divergent and polychromatic

31. What does 'monochromatic' mean in the context of laser light?

A) It consists of multiple colors. B) It consists of a single wavelength or color. C) It is highly intense. D) It spreads out rapidly.

32. What does 'coherent' mean in the context of laser light?

A) The light waves are out of phase with each other. B) The light waves are in phase and travel in the same direction. C) The light consists of only one color. D) The light is very weak.

33. Which of the following is a common application of lasers?

A) Medical surgery B) Barcode scanning C) Optical communication D) All of the above

34. What is the process by which a photon can stimulate an atom to emit a photon of the same frequency, phase, and direction?

A) Spontaneous emission B) Stimulated emission C) Absorption D) Scattering

35. What is the role of the 'gain medium' in a laser?

A) To provide energy to the system (pumping). B) To reflect light back and forth within the cavity. C) To amplify the light through stimulated emission. D) To convert electrical energy into light.

36. What is the term for the process of supplying energy to the gain medium of a laser?

A) Stimulation B) Population inversion C) Pumping D) Amplification

37. What is 'population inversion' in a laser?

A) More atoms in the lower energy state than the upper energy state. B) More atoms in the upper energy state than the lower energy state. C) All atoms are in the ground state. D) The laser is not functioning.

38. Which of the following is a type of electronic component that controls the flow of electric current?

A) Resistor B) Capacitor C) Inductor D) Transistor

39. What is the basic function of a semiconductor diode?

A) To amplify current B) To store electrical energy C) To allow current to flow in only one direction D) To oppose changes in current

40. What is an integrated circuit (IC)?

A) A single electronic component. B) A complex circuit fabricated on a single semiconductor chip. C) A device that converts AC to DC. D) A device that amplifies signals.

41. Which type of logic gate produces a HIGH output only if all inputs are HIGH?

A) AND gate B) OR gate C) NOT gate D) NAND gate

42. What is the primary function of a transistor?

A) To convert light into electricity B) To amplify or switch electronic signals and electrical power C) To store data D) To generate sound

43. What is the term for the transmission of information over a distance using electromagnetic waves?

A) Electronics B) Telephony C) Communications D) Networking

44. Which part of a communication system encodes the information into a signal?

A) Transmitter B) Receiver C) Channel D) Modulator

45. What is modulation in communication systems?

A) The process of converting an analog signal to digital. B) The process of combining a message signal with a carrier wave. C) The process of receiving a signal. D) The process of decoding information.

46. Which type of wave is commonly used for long-distance radio communication due to its ability to diffract around obstacles?

A) Microwaves B) Short waves (HF) C) Very low frequency (VLF) waves D) Infrared waves

47. What is the role of a receiver in a communication system?

A) To generate the message signal. B) To transmit the signal through the channel. C) To detect and decode the received signal. D) To modulate the carrier wave.

48. Which technology is fundamental to modern fiber optic communication?

A) Radio waves B) Microwaves C) Light D) Sound waves

49. What is the term for the unwanted disturbance that interferes with the desired signal in a communication system?

A) Modulation B) Demodulation C) Noise D) Bandwidth

Light sound heat nuclear physics laser electronics and communications. - Online Test

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