Q21. What is the primary function of a Dynamometer?
a) Measure force, power, or speed
b) Measure electric current
c) Measure wind speed
d) Measure sound intensity
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Correct Answer: a) Measure force, power, or speed
Explanation: A dynamometer is a device used to measure force, power, or speed. It can be employed in various applications, such as testing the performance of engines, motors, and other rotating prime movers. Dynamometers can also be used to determine the torque or power characteristics of a machine under test, as well as in emissions testing cycles for engines and powertrains.
Q22. What does an Electroencephalogram (EEG) primarily detect?
a) Electric current
b) Brain activity
c) Wind speed
d) Sound intensity
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Correct Answer: b) Brain activity
Explanation: An Electroencephalogram (EEG) is a test that records the electrical activity of the brain. Small sensors are attached to the scalp to pick up the electrical signals produced by the brain, which are then recorded by a machine. EEGs are primarily used to diagnose and monitor brain disorders, such as epilepsy and other seizure disorders.
Q23. What does an Electrometer measure?
a) Electric charge or electrical potential difference
b) Wind speed
c) Altitude
d) Sound intensity
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Correct Answer: a) Electric charge or electrical potential difference
Explanation: An electrometer is an electrical instrument used to measure electric charge or electrical potential difference. They are available in various types, ranging from historical handmade mechanical instruments to modern, highly sensitive electronic devices with extremely high input impedance. Electrometers are used in numerous applications, including nuclear physics experiments and the measurement of radiation with ionization chambers.
Q24. What is the primary function of an Electroscope?
a) Measure electric current
b) Detect the presence of an electric charge on a body
c) Measure wind speed
d) Measure sound intensity
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Correct Answer: b) Detect the presence of an electric charge on a body
Explanation: An electroscope is a scientific device used to detect the presence of an electric charge on a body. It operates based on the principle of electrostatic force, which causes the motion of a test charge within the electroscope. The device can also be considered a crude voltmeter, as it measures the electric charge of an object in relation to its capacitance.
Q25. What does an Electron Microscope primarily detect?
a) Electric current
b) Wind speed
c) Altitude
d) Detailed images of very small objects
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Correct Answer: d) Detailed images of very small objects
Explanation: An electron microscope is a type of microscope that uses a beam of electrons to create highly detailed images of very small objects, such as biological specimens and materials at the atomic level. Electron microscopes have much higher resolution and magnification capabilities than traditional light microscopes, allowing scientists to study structures and processes at the nanoscale.
Q26. What is the primary function of an Endoscope?
a) Measure electric current
b) Measure wind speed
c) Measure altitude
d) Examine the interior of a body cavity or organ
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Correct Answer: d) Examine the interior of a body cavity or organ
Explanation: An endoscope is a medical instrument used to examine the interior of a body cavity or organ. It consists of a flexible or rigid tube with a light and camera at the end, which allows the doctor to see inside the body. Endoscopes are used for various diagnostic and therapeutic procedures, such as bronchoscopy, colonoscopy, and laparoscopy.
Q27. What does a Fathometer measure?
a) Electric current
b) Wind speed
c) Depth of water
d) Sound intensity
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Correct Answer: c) Depth of water
Explanation: A fathometer is an instrument used to measure the depth of water by measuring the time it takes for a sound wave to travel from the surface to the bottom and back. It is commonly used in marine navigation, oceanography, and underwater exploration to determine water depth and create profiles of the seafloor.
Q28. What is the primary function of a Fluxmeter?
a) Measure changes in magnetic flux
b) Measure electric current
c) Measure wind speed
d) Measure sound intensity
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Correct Answer: a) Measure changes in magnetic flux
Explanation: A fluxmeter is an instrument that measures changes in magnetic flux, as detected through a coil arrangement, such as a Helmholtz coil. Fluxmeters are used in various applications, including the measurement of magnetic fields, quality control, and magnetic product sorting. They can also be used to plot the hysteresis loop and measure electric flux density.
Q29. What does a Galvanometer primarily detect?
a) Electric current
b) Wind speed
c) Altitude
d) Presence, direction, and magnitude of electric current in a conductor
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Correct Answer: d) Presence, direction, and magnitude of electric current in a conductor
Explanation: A galvanometer is a device used to detect the presence, direction, and magnitude of electric current in a conductor. It operates based on the principle of a current-carrying coil placed in a magnetic field, which experiences a torque that causes the needle or indicator to deflect. Galvanometers are used in various applications, such as detecting current flow in circuits and measuring the balance of currents in a Wheatstone bridge.
Q30. What does a Hydrometer measure?
a) Electric current
b) Wind speed
c) Specific gravity or relative density of liquids
d) Sound intensity
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Correct Answer: c) Specific gravity or relative density of liquids
Explanation: A hydrometer is an instrument used to measure the specific gravity or relative density of liquids, which is the ratio of the density of the liquid to the density of water. Hydrometers are typically calibrated and graduated with one or more scales corresponding to properties related to the density of the liquid. They are used in various industries, such as measuring the density of milk, sugar in a liquid, or alcohol content in spirits.