Q51. What is the primary function of a Pyrheliometer?
a) Measure electric current
b) Measure wind speed
c) Measure altitude
d) Measure direct beam solar irradiance
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Correct Answer: d) Measure direct beam solar irradiance
Explanation: A pyrheliometer is an instrument used to measure direct beam solar irradiance, which is the solar energy received directly from the sun. It consists of a thermopile, a device that converts thermal energy into electrical signals, and a window through which sunlight enters the instrument. Pyrheliometers are commonly used in solar energy systems to analyze variations in solar radiation productivity and to design and place solar panels.
Q52. What does a Pyrometer primarily measure?
a) High temperatures
b) Wind speed
c) Altitude
d) Sound intensity
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Correct Answer: a) High temperatures
Explanation: A pyrometer is an instrument used to measure relatively high temperatures, such as those encountered in furnaces. Most pyrometers work by measuring radiation from the body whose temperature is to be measured. Optical pyrometers, for example, measure the temperature of incandescent bodies by visually comparing them with a calibrated incandescent filament that can be adjusted in temperature.
Q53. What is the primary function of a Quadrant?
a) Measure electric current
b) Measure wind speed
c) Measure angles up to 90°
d) Measure sound intensity
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Correct Answer: c) Measure angles up to 90°
Explanation: A quadrant is an instrument used to measure angles up to 90°. Different versions of this instrument can be used to calculate various readings, such as longitude, latitude, and time of day. Quadrants were historically used in navigation, allowing sailors to measure the angle between an astronomical object and the horizon to determine their geographic position at sea.
Q54. What does Radar primarily detect?
a) Electric current
b) Objects and their location, distance, and speed
c) Altitude
d) Sound intensity
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Correct Answer: b) Objects and their location, distance, and speed
Explanation: Radar (RAdio Detection And Ranging) is an electromagnetic sensor used for detecting, locating, tracking, and recognizing objects of various kinds at considerable distances. It works by transmitting radio waves and receiving the reflected signals from objects. Radar has numerous applications, including military surveillance, air traffic control, weather observation, and navigation for ships and aircraft.
Q55. What is the primary function of a Radio Micrometer?
a) Measure electric current
b) Measure wind speed
c) Measure altitude
d) Measure small changes in radiant heat or temperature
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Correct Answer: d) Measure small changes in radiant heat or temperature
Explanation: A radio micrometer is an instrument used to measure small changes in radiant heat or temperature. It is a very sensitive modification or application of the thermopile, which is used for indicating minute changes of radiant heat or temperature.
Q56. What does a Refractometer primarily measure?
a) Electric current
b) Wind speed
c) Altitude
d) Refractive index or polarization of light in a sample
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Correct Answer: d) Refractive index or polarization of light in a sample
Explanation: A refractometer is an instrument used to measure a sample’s refractive index or polarization of light. It is commonly used in various applications, such as determining the concentration of solutes in solutions, assessing the purity of substances, and measuring the refractive index of liquids.
Q57. What is the primary function of a Salinometer?
a) Measure electric current
b) Measure wind speed
c) Measure altitude
d) Measure the salinity of a solution
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Correct Answer: d) Measure the salinity of a solution
Explanation: A salinometer, also known as a salinimeter or salimeter, is a device designed to measure the salinity or dissolved salt content of a solution. It often consists of a hydrometer or an ec meter and some means of converting those readings to a salinity reading. Salinometers are used in various applications, such as determining the concentration of salt in seawater and monitoring the salinity of fresh water produced by distillation of seawater.
Q58. What does a Sextant primarily measure?
a) Measure electric current
b) Measure wind speed
c) Measure altitude
d) Measure the angular distance between two visible objects
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Correct Answer: d) Measure the angular distance between two visible objects
Explanation: A sextant is a doubly reflecting navigation instrument that measures the angular distance between two visible objects. Its primary use is to measure the angle between an astronomical object and the horizon to determine a ship’s position at sea. Sextants are still used today by some nautical navigators and are the successors of the quadrant.
Q59. What is the primary function of a Sonar?
a) Measure electric current
b) Detect and locate objects underwater
c) Measure altitude
d) Measure sound intensity
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Correct Answer: b) Detect and locate objects underwater
Explanation: Sonar (SOund Navigation And Ranging) is a system that uses sound waves to detect and locate objects underwater. It works by emitting sound waves and listening for the echoes that return from objects in the water. Sonar is commonly used in various applications, such as underwater communication, navigation, and detection of submarines, ships, and other underwater objects.
Q60. What does a Spectroscope primarily detect?
a) Electric current
b) Wind speed
c) Altitude
d) Analyze the spectrum of light emitted or absorbed by a substance
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Correct Answer: d) Analyze the spectrum of light emitted or absorbed by a substance
Explanation: A spectroscope is an instrument used to analyze the spectrum of light emitted or absorbed by a substance. It works by dispersing light into its constituent wavelengths, allowing the observer to study the spectral lines and determine the composition, temperature, and other properties of the substance. Spectroscopes are used in various fields, such as chemistry, physics, and astronomy, to study the properties of materials and celestial objects.