26. What instrument measures radiant energy?
Correct Answer: B. Radiometer
Explanation: A radiometer detects and measures radiant energy, often used in experiments involving light or heat radiation.
27. Which instrument is used for the conversion of rays into mechanical energy?
Correct Answer: A. Radiometer
Explanation: A radiometer converts light rays into mechanical energy through the movement of vanes inside its glass bulb.
28. What instrument is used to measure the intensity of light?
Correct Answer: A. Luxmeter
Explanation: A luxmeter is used to measure the intensity of light, especially in workplaces, studios, and greenhouses.
29. Which instrument measures the amount of light?
Correct Answer: A. Illuminometer
Explanation: An illuminometer measures the total amount of light falling on a surface, often used in illumination studies.
30. Which instrument is used for observing very small and near objects?
Correct Answer: C. Microscope
Explanation: A microscope is used to observe very small objects or details that cannot be seen clearly with the naked eye.
31. Which instrument is used for measuring distant objects?
Correct Answer: A. Telescope
Explanation: A telescope is designed to view and measure distant objects by collecting and magnifying light.
32. Which instrument is used to measure electric current?
Correct Answer: A. Ammeter
Explanation: An ammeter measures the flow of electric current in a circuit, typically in amperes.
33. Which apparatus in submarines gives a clear view of objects on the surface?
Correct Answer: B. Periscope
Explanation: A periscope allows submarine crews to see above the water’s surface using mirrors or prisms.
34. What is used to measure the magnitude or intensity of earthquakes?
Correct Answer: B. Seismograph
Explanation: A seismograph records earthquake waves, while the Richter Scale quantifies their magnitude.
35. What instrument is used to measure ocean depth?
Correct Answer: A. Fathometer
Explanation: A fathometer measures the depth of the ocean using sound waves reflected from the sea floor.
36. Which instrument is used for measuring the flow of a fluid?
Correct Answer: C. Venturi Tube
Explanation: A Venturi tube measures the rate of fluid flow by observing pressure differences.
37. Which scientific instrument is used for observing and photographing the sun’s corona?
Correct Answer: A. Coronagraph
Explanation: A coronagraph blocks direct sunlight, allowing observation and photography of the sun’s corona.
38. What converts sound waves into electric energy?
Correct Answer: D. Microphone
Explanation: A microphone converts sound waves into electrical signals, enabling recording or amplification.
39. What scientific instrument measures the approximate height above the ground?
Correct Answer: B. Altimeter
Explanation: An altimeter measures altitude, commonly used in aircraft to determine height above sea level.
40. Which scientific instrument is used to measure the altitude of the sun?
Correct Answer: C. Sextant
Explanation: A sextant is used in navigation to measure the altitude of the sun and stars above the horizon.
41. When using a stethoscope to listen to a heartbeat, what sounds are heard?
Correct Answer: A. Closing of heart valves and blood flow
Explanation: A stethoscope picks up sounds created by the closing of heart valves and the flow of blood.
42. Which scientific instrument measures temperature by radiation?
Correct Answer: C. Pyrometer
Explanation: A pyrometer measures high temperatures by detecting thermal radiation.
43. Which scientific instrument is used to separate mixtures of chemicals?
Correct Answer: B. Centrifuge
Explanation: A centrifuge separates mixtures by spinning them at high speeds, causing denser substances to move outward.
44. Which scientific instrument receives radio waves from objects in space?
Correct Answer: A. Radio Telescope
Explanation: A radio telescope detects radio waves emitted by celestial objects in space.
45. Which scientific instrument measures the intensity of sound?
Correct Answer: A. Audiometer
Explanation: An audiometer is used to measure the intensity and frequency of sound, often for hearing tests.
46. Which scientific instrument is used to measure time?
Correct Answer: D. Chronometer
Explanation: A chronometer is a highly accurate instrument used to measure time.
47. Which scientific instrument detects the presence of electric charge?
Correct Answer: A. Electroscope
Explanation: An electroscope is used to detect and demonstrate the presence of electric charges.
48. What is used to view rapidly moving objects?
Correct Answer: A. Stroboscope
Explanation: A stroboscope allows observation of rapidly moving objects by producing flashes of light.
49. What scientific instrument is used to measure distance, elevations, and bearings during surveys?
Correct Answer: C. Tachometer
Explanation: A tachometer is used in surveying to measure distances, elevations, and angles.
50. Which scientific instrument determines the refractive power of lenses?
Correct Answer: B. Retinoscope
Explanation: A retinoscope is used in eye examinations to determine the refractive power of lenses.
51. The final image produced by a simple microscope is ___.
Correct Answer: D. Virtual and erect
Explanation: A simple microscope uses a convex lens to magnify objects. When the object is placed within the focal length of the lens, the image cannot be projected on a screen, making it virtual. The lens also makes the image appear upright, so it is erect. This is why simple microscopes are widely used for viewing small objects like biological samples.
52. Which scientific instrument detects light?
Correct Answer: B. Photodiode
Explanation: A photodiode works on the principle of the photoelectric effect. When light photons strike its surface, they generate electron-hole pairs, producing current. Because of this property, photodiodes are widely used in cameras, solar panels, and optical communication systems. They are highly sensitive to changes in light intensity, making them reliable detectors.
53. Which scientific instrument is used for analyzing polarized light?
Correct Answer: B. Polarizer
Explanation: Polarizers work by allowing only light waves oscillating in a specific direction to pass through. This helps in analyzing the polarization of light, which has applications in optics, photography, and scientific research. Polarization is important for reducing glare in sunglasses and improving contrast in optical instruments. Without polarizers, studying the orientation and behavior of polarized light would not be possible.
54. Which scientific instrument studies the spectrum of luminous bodies?
Correct Answer: A. Spectrometer
Explanation: A spectrometer separates light into its component wavelengths to produce a spectrum. This allows scientists to study the composition of stars, flames, or other luminous sources. The patterns of absorption and emission lines provide valuable information about chemical elements. Spectroscopy is a crucial tool in astronomy, chemistry, and physics for identifying substances and studying their properties.
55. Which scientific instrument converts low voltage to high voltage and vice versa?
Correct Answer: A. Transformer
Explanation: Transformers work on the principle of electromagnetic induction. By adjusting the number of turns in the primary and secondary coils, voltage can be stepped up or stepped down. They are vital for transmitting electrical power over long distances, as high voltage minimizes energy loss. Without transformers, efficient electricity distribution would not be possible.
56. Which scientific instrument is used to observe the retina?
Correct Answer: C. Ophthalmoscope
Explanation: The ophthalmoscope directs light into the eye and uses lenses to magnify the retina. This allows doctors to check for diseases such as diabetic retinopathy, glaucoma, and retinal detachment. It provides a clear view of blood vessels and the optic nerve. Regular retinal observation is critical for early detection of eye-related health issues.
57. What is the principle of sonar?
Correct Answer: C. Reflection or echo of sound
Explanation: SONAR (Sound Navigation and Ranging) involves sending sound waves underwater and measuring the time taken for the echo to return. The reflection of sound helps in determining the distance and shape of underwater objects. It is widely used in submarines, navigation, and fish finding. The same principle also aids in mapping the ocean floor and detecting obstacles.
Scientific Instruments MCQs are an integral part of competitive exams, especially in the General Science section, where they test an aspirant’s knowledge of the tools used in scientific research and practical applications.
These questions are commonly asked to evaluate the understanding of various instruments like microscopes, thermometers, barometers, and voltmeters, along with their uses and measurements.
Mastering scientific instruments MCQs can significantly impact an aspirant’s score, as they often account for a considerable portion of the exam, helping candidates stand out. The knowledge of scientific instruments also plays a vital role in job hunting, particularly in fields like research, engineering, healthcare, and laboratories, where a deep understanding of these tools is crucial for practical work.
In competitive exams, every mark counts—one mark can make your placement and keep you in the competition, while that same one mark can also make you out of the competition. Therefore, preparing thoroughly for these MCQs is essential. To make this process easier for aspirants, our team has prepared a comprehensive list of MCQs on scientific instruments, ensuring you are well-equipped to succeed in your exams.