{"id":12656,"date":"2025-09-20T05:59:08","date_gmt":"2025-09-20T04:59:08","guid":{"rendered":"https:\/\/mcqsadda.com\/?p=12656"},"modified":"2025-10-22T09:56:56","modified_gmt":"2025-10-22T08:56:56","slug":"scientific-instruments-top-100-mcqs-with-answer-and-explanation","status":"publish","type":"post","link":"https:\/\/mcqsadda.com\/index.php\/2025\/09\/20\/scientific-instruments-top-100-mcqs-with-answer-and-explanation\/","title":{"rendered":"Scientific Instruments Top 100 MCQs With Answer and Explanation"},"content":{"rendered":"\n

1. The instrument used to measure current is called:<\/mark><\/strong>
a) Voltmeter
b) Ammeter
c) Galvanometer
d) Wattmeter
Answer:<\/strong> b
Explanation:<\/strong> Ammeter measures electric current in a circuit.<\/p>\n\n\n\n

2. The instrument used to measure potential difference is:<\/mark><\/strong>
a) Voltmeter
b) Ammeter
c) Galvanometer
d) Ohmmeter
Answer:<\/strong> a
Explanation:<\/strong> Voltmeter is connected in parallel to measure voltage.<\/p>\n\n\n\n

3. A galvanometer measures:<\/mark><\/strong>
a) Current
b) Voltage
c) Resistance
d) Power
Answer:<\/strong> a
Explanation:<\/strong> Galvanometer measures small currents; can be converted to ammeter or voltmeter.<\/p>\n\n\n\n

4. Conversion of galvanometer to ammeter is done by:<\/mark><\/strong>
a) Series resistor
b) Parallel resistor
c) No resistor
d) Capacitor
Answer:<\/strong> b
Explanation:<\/strong> Low-resistance shunt is connected parallel to galvanometer.<\/p>\n\n\n\n

5. Conversion of galvanometer to voltmeter is done by:<\/mark><\/strong>
a) Series resistor
b) Parallel resistor
c) No resistor
d) Inductor
Answer:<\/strong> a
Explanation:<\/strong> High series resistance is added to galvanometer to measure voltage.<\/p>\n\n\n\n

6. The tangent galvanometer measures:<\/mark><\/strong>
a) Electric field
b) Magnetic field
c) Electric current
d) Resistance
Answer:<\/strong> c
Explanation:<\/strong> Measures current using the tangent law of magnetism.<\/p>\n\n\n\n

7. Ballistic galvanometer is used to measure:<\/mark><\/strong>
a) Steady current
b) Charge
c) Voltage
d) Resistance
Answer:<\/strong> b
Explanation:<\/strong> Measures total charge passed through in short time.<\/p>\n\n\n\n

8. A potentiometer is used to measure:<\/mark><\/strong>
a) Voltage
b) Current
c) Charge
d) Resistance
Answer:<\/strong> a
Explanation:<\/strong> Potentiometer measures emf or potential difference accurately without drawing current.<\/p>\n\n\n\n

9. The Wheatstone bridge measures:<\/mark><\/strong>
a) Current
b) Resistance
c) Voltage
d) Power
Answer:<\/strong> b
Explanation:<\/strong> Wheatstone bridge determines unknown resistance by balancing ratio of resistances.<\/p>\n\n\n\n

10. Kelvin double bridge is used to measure:<\/mark><\/strong>
a) Low resistance
b) High resistance
c) Voltage
d) Current
Answer:<\/strong> a
Explanation:<\/strong> Used for very low resistance measurements.<\/p>\n\n\n\n

11. Carey-Foster bridge measures:<\/mark><\/strong>
a) Very high resistance
b) Very low resistance
c) Medium resistance
d) Inductance
Answer:<\/strong> c
Explanation:<\/strong> Used for medium resistance measurement and comparison.<\/p>\n\n\n\n

12. A thermocouple measures:<\/mark><\/strong>
a) Electric current
b) EMF
c) Temperature
d) Magnetic field
Answer:<\/strong> c
Explanation:<\/strong> Generates EMF proportional to temperature difference between junctions.<\/p>\n\n\n\n

13. Thermistor is:<\/mark><\/strong>
a) A device whose resistance increases with temperature
b) A device whose resistance decreases with temperature
c) Measures EMF
d) Measures pressure
Answer:<\/strong> b
Explanation:<\/strong> Negative temperature coefficient; resistance decreases with temperature rise.<\/p>\n\n\n\n

14. Strain gauge measures:<\/mark><\/strong>
a) Pressure
b) Force
c) Strain
d) Voltage
Answer:<\/strong> c
Explanation:<\/strong> Resistance of strain gauge changes when stretched; used to measure strain.<\/p>\n\n\n\n

15. Microammeter is used to measure:<\/mark><\/strong>
a) Large currents
b) Small currents
c) Voltage
d) Power
Answer:<\/strong> b
Explanation:<\/strong> Measures microamperes (small currents).<\/p>\n\n\n\n

16. Milliammeter measures:<\/mark><\/strong>
a) Microamperes
b) Milliamperes
c) Amperes
d) Voltage
Answer:<\/strong> b
Explanation:<\/strong> Measures current in milliampere range.<\/p>\n\n\n\n

17. The main part of a moving coil galvanometer is:<\/mark><\/strong>
a) Coil suspended in magnetic field
b) Permanent magnet
c) Resistor
d) Capacitor
Answer:<\/strong> a
Explanation:<\/strong> Coil carrying current experiences torque in magnetic field.<\/p>\n\n\n\n

18. D\u2019Arsonval galvanometer operates on:<\/mark><\/strong>
a) Moving coil principle
b) Moving iron principle
c) Electrostatic principle
d) Induction principle
Answer:<\/strong> a
Explanation:<\/strong> Uses torque on current-carrying coil in magnetic field.<\/p>\n\n\n\n

19. Moving iron instrument measures:<\/mark><\/strong>
a) Current only
b) AC and DC
c) Voltage only
d) Resistance
Answer:<\/strong> b
Explanation:<\/strong> Can measure both AC and DC because force depends on square of current.<\/p>\n\n\n\n

20. PMMC instruments are:<\/mark><\/strong>
a) Only for AC
b) Only for DC
c) For both AC and DC
d) None
Answer:<\/strong> b
Explanation:<\/strong> Permanent Magnet Moving Coil instruments work for DC only.<\/p>\n\n\n\n

21. Rheostat is used to:<\/mark><\/strong>
a) Measure voltage
b) Vary current
c) Measure resistance
d) Detect EMF
Answer:<\/strong> b
Explanation:<\/strong> Variable resistor used to control current in circuit.<\/p>\n\n\n\n

22. Multimeter can measure:<\/mark><\/strong>
a) Current, voltage, resistance
b) Current only
c) Voltage only
d) Resistance only
Answer:<\/strong> a
Explanation:<\/strong> Combines ammeter, voltmeter, ohmmeter in one instrument.<\/p>\n\n\n\n

23. Ammeter should be connected:<\/mark><\/strong>
a) In series
b) In parallel
c) Across load
d) Anywhere
Answer:<\/strong> a
Explanation:<\/strong> Series connection ensures all current passes through ammeter.<\/p>\n\n\n\n

24. Voltmeter should be connected:<\/mark><\/strong>
a) In series
b) In parallel
c) Across resistor only
d) In any way
Answer:<\/strong> b
Explanation:<\/strong> Parallel connection measures potential difference across component.<\/p>\n\n\n\n

25. The accuracy of an instrument is defined as:<\/mark><\/strong>
a) Ability to measure rapidly
b) Degree of closeness to true value
c) Ability to measure large values
d) Ability to measure small values
Answer:<\/strong> b
Explanation:<\/strong> Accuracy = closeness of measured value to true value.<\/p>\n\n\n\n

26. A PMMC instrument can measure:<\/mark><\/strong>
a) AC only
b) DC only
c) Both AC and DC
d) Resistance only
Answer:<\/strong> b
Explanation:<\/strong> Permanent Magnet Moving Coil instruments work only for DC.<\/p>\n\n\n\n

27. Moving iron instruments can measure<\/mark><\/strong>:
a) DC only
b) AC only
c) Both AC and DC
d) Voltage only
Answer:<\/strong> c
Explanation:<\/strong> Moving iron instruments respond to square of current, so they work for both AC and DC.<\/p>\n\n\n\n

28. The main principle of voltmeter and ammeter is:<\/mark><\/strong>
a) Electromagnetic induction
b) Deflection proportional to current
c) Electrostatic force
d) Magnetic flux
Answer:<\/strong> b
Explanation:<\/strong> Current passing through coil produces proportional deflection.<\/p>\n\n\n\n

29. Shunt resistance in an ammeter is used to:<\/mark><\/strong>
a) Increase current sensitivity
b) Reduce current sensitivity
c) Convert galvanometer to ammeter
d) Protect voltage
Answer:<\/strong> c
Explanation:<\/strong> Shunt allows most current to bypass galvanometer.<\/p>\n\n\n\n

30. Series resistance in voltmeter is used to:<\/mark><\/strong>
a) Increase sensitivity
b) Reduce sensitivity
c) Convert voltmeter to ammeter
d) Protect ammeter
Answer:<\/strong> a
Explanation:<\/strong> High series resistance limits current, allowing voltage measurement.<\/p>\n\n\n\n

31. Earth leakage circuit breaker (ELCB) protects:<\/mark><\/strong>
a) Voltage surges
b) Overcurrent
c) Leakage current to earth
d) Transformer
Answer:<\/strong> c
Explanation:<\/strong> Detects current leakage and disconnects supply.<\/p>\n\n\n\n

32. A kilowatt-hour meter measures:<\/mark><\/strong>
a) Power
b) Energy
c) Voltage
d) Current
Answer:<\/strong> b
Explanation:<\/strong> Measures energy consumption (kWh = power \u00d7 time).<\/p>\n\n\n\n

33. Energy meter works on:<\/mark><\/strong>
a) Moving coil principle
b) Electromagnetic induction
c) Electrostatic principle
d) Magnetic saturation
Answer:<\/strong> b
Explanation:<\/strong> Uses induction principle: current and voltage coils produce torque proportional to power.<\/p>\n\n\n\n

34. Ohmmeter measures:<\/mark><\/strong>
a) Resistance directly
b) Current only
c) Voltage only
d) Power
Answer:<\/strong> a
Explanation:<\/strong> Measures resistance by passing known current through unknown resistor.<\/p>\n\n\n\n

35. Megger is used to measure:<\/mark><\/strong>
a) Low resistance
b) High resistance and insulation
c) Voltage
d) Current
Answer:<\/strong> b
Explanation:<\/strong> High voltage is applied to measure insulation resistance.<\/p>\n\n\n\n

36. The unit of electrical resistance is:<\/mark><\/strong>
a) Ohm
b) Farad
c) Henry
d) Volt
Answer:<\/strong> a
Explanation:<\/strong> 1 \u03a9 = 1 V\/A.<\/p>\n\n\n\n

37. The Wheatstone bridge is used for:<\/mark><\/strong>
a) Measuring voltage
b) Measuring resistance
c) Measuring current
d) Measuring power
Answer:<\/strong> b
Explanation:<\/strong> Determines unknown resistance by balancing a bridge circuit.<\/p>\n\n\n\n

38. Kelvin double bridge is preferred for<\/mark><\/strong>:<\/mark>
a) Medium resistance
b) High resistance
c) Very low resistance
d) Inductance
Answer:<\/strong> c
Explanation:<\/strong> Measures very low resistances accurately by minimizing contact resistance errors.<\/p>\n\n\n\n

39. Maxwell\u2019s bridge is used to measure:<\/mark><\/strong>
a) Resistance
b) Inductance
c) Capacitance
d) Voltage
Answer:<\/strong> b
Explanation:<\/strong> Determines unknown inductance using a bridge with standard capacitance.<\/p>\n\n\n\n

40. Schering bridge is used to measure:<\/mark><\/strong>
a) Capacitance and dissipation factor
b) Inductance
c) Resistance
d) Voltage
Answer:<\/strong> a
Explanation:<\/strong> Measures capacitor parameters precisely.<\/p>\n\n\n\n

41. Megger works on:<\/mark><\/strong>
a) Moving coil
b) Electrostatic
c) Permanent magnet
d) Electromagnetic induction
Answer:<\/strong> d
Explanation:<\/strong> High-voltage DC generated by hand-cranked dynamo.<\/p>\n\n\n\n

42. Ammeter should have:<\/mark><\/strong>
a) High resistance
b) Low resistance
c) Medium resistance
d) Variable resistance
Answer:<\/strong> b
Explanation:<\/strong> Low resistance ensures minimal voltage drop in series.<\/p>\n\n\n\n

43. Voltmeter should have:<\/mark><\/strong>
a) High resistance
b) Low resistance
c) Medium resistance
d) Zero resistance
Answer:<\/strong> a
Explanation:<\/strong> High resistance prevents current draw from circuit.<\/p>\n\n\n\n

44. AC energy meter can measure:<\/mark><\/strong>
a) Instantaneous power
b) Average power
c) RMS power
d) Maximum power
Answer:<\/strong> c
Explanation:<\/strong> Measures average energy consumed over time using RMS values.<\/p>\n\n\n\n

45. Rectifier type PMMC instruments can measure:<\/mark><\/strong>
a) AC only
b) DC only
c) AC and DC
d) Resistance only
Answer:<\/strong> c
Explanation:<\/strong> AC is converted to DC by rectifier for PMMC deflection.<\/p>\n\n\n\n

46. LCR meter measures:<\/mark><\/strong>
a) Inductance, capacitance, resistance
b) Voltage only
c) Current only
d) Power only
Answer:<\/strong> a
Explanation:<\/strong> LCR meters provide precise measurement of L, C, and R.<\/p>\n\n\n\n

47. The main purpose of a potentiometer is:<\/mark><\/strong>
a) Measure current
b) Measure potential difference accurately
c) Measure resistance only
d) Measure power
Answer:<\/strong> b
Explanation:<\/strong> Measures EMF or potential difference without drawing current.<\/p>\n\n\n\n

48. Capacitance can be measured by:<\/mark><\/strong>
a) Wheatstone bridge
b) Schering bridge
c) Kelvin bridge
d) LCR meter
Answer:<\/strong> b
Explanation:<\/strong> Schering bridge or LCR meter used for precise capacitance measurement.<\/p>\n\n\n\n

49. Galvanometer sensitivity is measured in:<\/mark><\/strong>
a) Ohms
b) Volt\/ampere
c) Deflection per unit current
d) Farad
Answer:<\/strong> c
Explanation:<\/strong> Sensitivity = deflection per unit current (e.g., mm\/\u03bcA).<\/p>\n\n\n\n

50. Digital multimeter works on:<\/mark><\/strong>
a) Moving coil principle
b) Analog pointer
c) Analog-to-digital conversion
d) LCR principle
Answer:<\/strong> c
Explanation:<\/strong> Converts analog signals to digital display using ADC.<\/p>\n\n\n\n

51. Spectrometer is used to measure:<\/mark><\/strong>
a) Current
b) Wavelength of light
c) Resistance
d) Voltage
Answer:<\/strong> b
Explanation:<\/strong> Spectrometer accurately measures angles of light deviation to determine wavelength.<\/p>\n\n\n\n

52. A telescope is used to:<\/mark><\/strong>
a) Observe distant objects
b) Measure current
c) Measure voltage
d) Measure resistance
Answer:<\/strong> a
Explanation:<\/strong> Collects and magnifies light from distant objects.<\/p>\n\n\n\n

53. A microscope increases:<\/mark><\/strong>
a) Voltage
b) Current
c) Image magnification
d) Resistance
Answer:<\/strong> c
Explanation:<\/strong> Microscope magnifies small objects using lenses.<\/p>\n\n\n\n

54. Plane mirror produces:<\/mark><\/strong>
a) Real image
b) Virtual image
c) Both
d) No image
Answer:<\/strong> b
Explanation:<\/strong> Plane mirror produces upright virtual image behind mirror.<\/p>\n\n\n\n

55. Concave mirror can produce:<\/mark><\/strong>
a) Real image only
b) Virtual image only
c) Real or virtual image depending on object position
d) No image
Answer:<\/strong> c
Explanation:<\/strong> Object beyond focus \u2192 real, inverted; object inside focus \u2192 virtual, upright.<\/p>\n\n\n\n

56. Convex lens produces:<\/mark><\/strong>
a) Real image
b) Virtual image
c) Both
d) No image
Answer:<\/strong> c
Explanation:<\/strong> Object beyond focal length \u2192 real image; inside focal length \u2192 virtual image.<\/p>\n\n\n\n

57. Focal length of lens is measured by:<\/mark><\/strong>
a) Meter scale
b) Convex lens formula
c) Lens maker\u2019s formula
d) Spectrometer
Answer:<\/strong> c
Explanation:<\/strong> <\/p>\n\n\n\n

58. Prism is used to:<\/mark><\/strong>
a) Split light into spectrum
b) Measure current
c) Measure voltage
d) Measure resistance
Answer:<\/strong> a
Explanation:<\/strong> Dispersion separates light into constituent colors.<\/p>\n\n\n\n

59. Refractive index of medium is:<\/mark><\/strong>
a) Ratio of speed in medium to air
b) Ratio of speed in air to medium
c) Ratio of wavelength in medium to air
d) None
Answer:<\/strong> b
Explanation:<\/strong> , speed of light in vacuum or air divided by speed in medium.<\/p>\n\n\n\n

60. Spectrophotometer is used to measure:<\/mark><\/strong>
a) Wavelength of X-rays
b) Absorbance of light by solution
c) Current
d) Voltage
Answer:<\/strong> b
Explanation:<\/strong> Measures intensity of light transmitted through a sample.<\/p>\n\n\n\n

61. Photometer measures:<\/mark><\/strong>
a) Current
b) Brightness of light
c) Resistance
d) Capacitance
Answer:<\/strong> b
Explanation:<\/strong> Photometer measures luminous intensity or brightness.<\/p>\n\n\n\n

62. Interference of light is observed using:<\/mark><\/strong>
a) Telescope
b) Michelson interferometer
c) Spectrometer
d) Ammeter
Answer:<\/strong> b
Explanation:<\/strong> Michelson interferometer produces fringe patterns for wavelength measurement.<\/p>\n\n\n\n

63. Diffraction of light is studied using:<\/mark><\/strong>
a) Grating
b) Single slit
c) Polarizer
d) Lens
Answer:<\/strong> b
Explanation:<\/strong> Single slit diffraction causes spreading and fringes.<\/p>\n\n\n\n

64. Polarizer is used to:<\/mark><\/strong>
a) Split light
b) Convert unpolarized light to polarized light
c) Measure intensity
d) Measure wavelength
Answer:<\/strong> b
Explanation:<\/strong> Polarizer allows only electric field along certain direction to pass.<\/p>\n\n\n\n

65. Optical fiber works on:<\/mark><\/strong>
a) Diffraction
b) Total internal reflection
c) Polarization
d) Refraction
Answer:<\/strong> b
Explanation:<\/strong> Light is guided inside core by total internal reflection.<\/p>\n\n\n\n

66. X-ray tube works on:<\/mark><\/strong>
a) Electron acceleration and deceleration
b) Electron capture
c) Alpha decay
d) Gamma emission
Answer:<\/strong> a
Explanation:<\/strong> High-speed electrons strike target; sudden deceleration produces X-rays.<\/p>\n\n\n\n

67. Geiger-M\u00fcller counter detects:<\/mark><\/strong>
a) Voltage
b) Current
c) Ionizing radiation
d) Resistance
Answer:<\/strong> c
Explanation:<\/strong> Detects \u03b1, \u03b2, \u03b3 radiation using ionization in gas.<\/p>\n\n\n\n

68. Scintillation counter uses:<\/mark><\/strong>
a) Fluorescent screen
b) Ionization
c) Magnetic field
d) Thermistor
Answer:<\/strong> a
Explanation:<\/strong> Detects radiation via light flashes in scintillator crystal.<\/p>\n\n\n\n

69. Photomultiplier tube amplifies:<\/mark><\/strong>
a) Light signal
b) Current
c) Voltage
d) Resistance
Answer:<\/strong> a
Explanation:<\/strong> Converts weak light signals into amplified electric signals.<\/p>\n\n\n\n

70. X-ray diffraction is used to study:<\/mark><\/strong>
a) Resistance
b) Crystal structure
c) Voltage
d) Current
Answer:<\/strong> b
Explanation:<\/strong> X-rays interact with crystal lattice, giving diffraction patterns.<\/p>\n\n\n\n

71. Bragg\u2019s law is<\/mark><\/strong>:
a)
b)
c)
d)
Answer:<\/strong> a
Explanation:<\/strong> Describes constructive interference of X-rays in crystal planes.<\/p>\n\n\n\n

72. Cloud chamber is used to observe:<\/mark><\/strong>
a) Electric current
b) Path of ionizing particles
c) Light intensity
d) Voltage
Answer:<\/strong> b
Explanation:<\/strong> Tracks left by \u03b1, \u03b2 particles in supersaturated vapor.<\/p>\n\n\n\n

73. Wilson cloud chamber uses<\/mark><\/strong>:<\/mark>
a) Supersaturated vapor
b) Condensed water only
c) Gas discharge
d) Laser
Answer:<\/strong> a
Explanation:<\/strong> Vapor condenses along ionized paths of radiation.<\/p>\n\n\n\n

74. Bubble chamber is filled with:<\/mark><\/strong>
a) Water
b) Superheated liquid
c) Gas
d) Metal
Answer:<\/strong> b
Explanation:<\/strong> Charged particles leave trails of bubbles in superheated liquid.<\/p>\n\n\n\n

75. Geiger-M\u00fcller counter cannot measure:<\/mark><\/strong>
a) Alpha
b) Beta
c) Gamma
d) Neutrinos
Answer:<\/strong> d
Explanation:<\/strong> Neutrinos interact very weakly; undetectable by GM counter.<\/p>\n\n\n\n

76. Digital multimeter works on:<\/mark><\/strong>
a) Moving coil principle
b) Moving iron principle
c) Analog-to-digital conversion
d) Electrostatic principle
Answer:<\/strong> c
Explanation:<\/strong> Converts analog signals to digital display using ADC circuits.<\/p>\n\n\n\n

77. CRO (Cathode Ray Oscilloscope) measures:<\/mark><\/strong>
a) Voltage vs time
b) Current vs resistance
c) Power vs voltage
d) Energy
Answer:<\/strong> a
Explanation:<\/strong> CRO displays variation of voltage over time on screen.<\/p>\n\n\n\n

78. CRO works on:<\/mark><\/strong>
a) Cathode ray tube
b) Moving coil
c) Moving iron
d) Electrostatic principle
Answer:<\/strong> a
Explanation:<\/strong> Uses electron beam deflection in CRT to display signals.<\/p>\n\n\n\n

79. Storage oscilloscope is used to:<\/mark><\/strong>
a) Measure DC only
b) Capture and store transient signals
c) Measure resistance
d) Measure current
Answer:<\/strong> b
Explanation:<\/strong> Can hold and display rapidly varying or transient signals.<\/p>\n\n\n\n

80. Lissajous figures on CRO are used to determine:<\/mark><\/strong>
a) Resistance
b) Frequency ratio and phase difference
c) Voltage only
d) Current only
Answer:<\/strong> b
Explanation:<\/strong> Patterns formed on CRO by two perpendicular signals reveal frequency and phase relation.<\/p>\n\n\n\n

81. Digital frequency meter measures:<\/mark><\/strong>
a) Voltage
b) Frequency
c) Resistance
d) Current
Answer:<\/strong> b
Explanation:<\/strong> Counts number of cycles per second of periodic signal.<\/p>\n\n\n\n

82. Phase sequence indicator is used in:<\/mark><\/strong>
a) DC circuits
b) Three-phase AC systems
c) Single-phase AC circuits
d) Transformers only
Answer:<\/strong> b
Explanation:<\/strong> Determines correct phase rotation in three-phase systems.<\/p>\n\n\n\n

83. Digital storage oscilloscope (DSO) converts:<\/mark><\/strong>
a) Voltage to current
b) Analog waveform to digital waveform
c) AC to DC
d) None
Answer:<\/strong> b
Explanation:<\/strong> Captures, digitizes, and stores signal for display and analysis.<\/p>\n\n\n\n

84. Hall effect sensor measures:<\/mark><\/strong>
a) Current only
b) Magnetic field
c) Voltage only
d) Resistance
Answer:<\/strong> b
Explanation:<\/strong> Produces voltage perpendicular to current in magnetic field.<\/p>\n\n\n\n

85. Digital thermometer works on:<\/mark><\/strong>
a) Thermocouple and ADC
b) Mercury
c) Alcohol expansion
d) Resistance only
Answer:<\/strong> a
Explanation:<\/strong> Thermocouple produces EMF converted to temperature digitally.<\/p>\n\n\n\n

86. Gauss meter measures:<\/mark><\/strong>
a) Electric field
b) Magnetic field
c) Voltage
d) Current
Answer:<\/strong> b
Explanation:<\/strong> Measures magnetic flux density (in Gauss or Tesla).<\/p>\n\n\n\n

87. Photoelectric cell converts:<\/mark><\/strong>
a) Light energy to heat
b) Light energy to electrical energy
c) Electrical energy to light
d) Sound to electrical energy
Answer:<\/strong> b
Explanation:<\/strong> Emits electrons when exposed to light (photoelectric effect).<\/p>\n\n\n\n

88. Laser is used in:<\/mark><\/strong>
a) Communication
b) Surgery
c) Cutting metals
d) All of the above
Answer:<\/strong> d
Explanation:<\/strong> Coherent light with high intensity has multiple applications.<\/p>\n\n\n\n

89. Fiber optic sensor detects:<\/mark><\/strong>
a) Light only
b) Temperature, pressure, displacement via light modulation
c) Current
d) Voltage
Answer:<\/strong> b
Explanation:<\/strong> Light intensity or phase changes are used to sense physical quantities.<\/p>\n\n\n\n

90. CCD (Charge Coupled Device) is used in:<\/mark><\/strong>
a) Digital cameras and imaging
b) Resistance measurement
c) Thermometry
d) Voltmeter
Answer:<\/strong> a
Explanation:<\/strong> Converts optical image into electronic signal in cameras or telescopes.<\/p>\n\n\n\n

91. Interferometer is used to measure:<\/mark><\/strong>
a) Distance, wavelength, refractive index
b) Current
c) Voltage
d) Resistance
Answer:<\/strong> a
Explanation:<\/strong> Uses interference of light to measure precise physical quantities.<\/p>\n\n\n\n

92. Michelson interferometer was used to measure:
<\/mark><\/strong>a) Speed of light
b) Wavelength of light
c) Electric current
d) Voltage
Answer:<\/strong> a
Explanation:<\/strong> Michelson-Morley experiment used it to detect ether; can measure wavelength and light speed.<\/p>\n\n\n\n

93. Ultrasonic detector uses:<\/mark><\/strong>
a) Sound waves >20 kHz
b) Light waves
c) Electric waves
d) Magnetic waves
Answer:<\/strong> a
Explanation:<\/strong> Detects high-frequency sound waves above human hearing.<\/p>\n\n\n\n

94. Thermocouple pyrometer measures:<\/mark><\/strong>
a) Low temperature
b) High temperature
c) Current
d) Voltage
Answer:<\/strong> b
Explanation:<\/strong> Measures high temperatures using EMF produced by thermocouple.<\/p>\n\n\n\n

95. Pyrometer measures:
<\/mark><\/strong>a) Electric current
b) Temperature of hot bodies without contact
c) Resistance
d) Voltage
Answer:<\/strong> b
Explanation:<\/strong> Non-contact measurement via radiation emitted from hot object.<\/p>\n\n\n\n

96. Atomic absorption spectrometer measures:<\/mark><\/strong>
a) Concentration of elements in sample
b) Voltage
c) Current
d) Resistance
Answer:<\/strong> a
Explanation:<\/strong> Measures light absorbed by atoms vaporized in flame or furnace.<\/p>\n\n\n\n

97. Mass spectrometer is used to measure:<\/mark><\/strong>
a) Mass-to-charge ratio of ions
b) Voltage
c) Current
d) Resistance
Answer:<\/strong> a
Explanation:<\/strong> Separates ions based on mass\/charge ratio using magnetic\/electric fields.<\/p>\n\n\n\n

98. Geiger-M\u00fcller counter detects:<\/mark><\/strong>
a) Neutrinos
b) Ionizing radiation
c) Magnetic field
d) Electric field
Answer:<\/strong> b
Explanation:<\/strong> Detects \u03b1, \u03b2, \u03b3 radiation by ionization in gas-filled tube.<\/p>\n\n\n\n

99. Scintillation detector uses:<\/mark><\/strong>
a) Light emission in crystal
b) Thermal effect
c) Magnetic deflection
d) Resistance variation
Answer:<\/strong> a
Explanation:<\/strong> Radiation produces light pulses in scintillator; converted to electrical signal.<\/p>\n\n\n\n

100. Modern scientific instruments often combine:<\/mark><\/strong>
a) Analog measurement only
b) Digital display, data acquisition, and automation
c) Mechanical measurement only
d) None
Answer:<\/strong> b
Explanation:<\/strong> Advanced instruments integrate sensors, ADCs, display, and computer interface for precision and convenience.<\/p>\n\n\n","protected":false},"excerpt":{"rendered":"

1. The instrument used to measure current is called:a) Voltmeterb) Ammeterc) Galvanometerd) WattmeterAnswer: bExplanation: Ammeter measures electric current in a circuit. 2. The instrument used to measure potential difference is:a) Voltmeterb) Ammeterc) Galvanometerd) OhmmeterAnswer: aExplanation: Voltmeter is connected in parallel to measure voltage. 3. A galvanometer measures:a) Currentb) Voltagec) Resistanced) PowerAnswer: aExplanation: Galvanometer measures small<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"[]"},"categories":[8],"tags":[15723,15481,15763,15770,15774,4029,5649,5652,15465,5623,15777,15768,15772,15766,15769,15471,15775,15536,15479,15474,15467,15483,15472,15592,15456,15771,15478,15765,10957,15776,15764,15469,15773,15480,15767],"class_list":{"0":"post-12656","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-physics","7":"tag-ammeter-and-voltmeter","8":"tag-competitive-exam-physics","9":"tag-galvanometer","10":"tag-instruments-problems","11":"tag-lab-instruments","12":"tag-mcqs-adda","13":"tag-mcqs-for-pc-psi-sda-fda-pdo-vao-banking-kas-ias-ssc-gd-ssc-chsl-ssc-cgl-for-all-compitative-exams","14":"tag-mcqs-for-pc-psi-sda-fda-pdo-vao-banking-kas-ias-ssc-gd-ssc-chsl-ssc-cgl-for-all-compitative-examsin-kannada","15":"tag-mcqs-for-physics-exam","16":"tag-mcqs-for-sda-fda-pdo-vao-banking-kas-ias-ssc-gd-ssc-chsl-ssc-cgl-for-all-compitative-exams","17":"tag-measurement-accuracy","18":"tag-measurement-instruments","19":"tag-meter-scale","20":"tag-micrometer-screw-gauge","21":"tag-multimeter","22":"tag-physics-basics","23":"tag-physics-experiments","24":"tag-physics-formulas","25":"tag-physics-learning","26":"tag-physics-mcqs","27":"tag-physics-preparation-material","28":"tag-physics-questions-and-answers","29":"tag-physics-quiz","30":"tag-physics-revision","31":"tag-physics-study-material","32":"tag-precision-instruments","33":"tag-psc-physics-mcqs","34":"tag-scientific-instruments-in-physics","35":"tag-scientific-instruments-top-100-mcqs-with-answer-and-explanation","36":"tag-scientific-tools","37":"tag-screw-gauge","38":"tag-ssc-physics-mcqs","39":"tag-stop-watch","40":"tag-upsc-physics-mcqs","41":"tag-vernier-calipers"},"_links":{"self":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12656","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/comments?post=12656"}],"version-history":[{"count":2,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12656\/revisions"}],"predecessor-version":[{"id":12701,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12656\/revisions\/12701"}],"wp:attachment":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/media?parent=12656"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/categories?post=12656"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/tags?post=12656"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}