The spot on CRO screen is deflected horizontally by

 

ELECTRICAL & ELECTRONIC MEASUREMENTS 

Q201. The unit of resistance is
A) Volt
B) Ohm
C) Ampere
D) Farad
Answer: B

Q202. The instrument used to measure current is
A) Voltmeter
B) Ammeter
C) Wattmeter
D) Ohmmeter
Answer: B

Q203. The instrument used to measure voltage is
A) Ammeter
B) Voltmeter
C) Wattmeter
D) Multimeter
Answer: B

Q204. The instrument used to measure power is
A) Ammeter
B) Wattmeter
C) Voltmeter
D) Ohmmeter
Answer: B

Q205. The unit of power is
A) Joule
B) Volt
C) Watt
D) Ohm
Answer: C

Q206. The unit of energy is
A) Watt
B) Joule
C) Volt
D) Coulomb
Answer: B

Q207. The instrument used to measure resistance is
A) Wattmeter
B) Ammeter
C) Ohmmeter
D) Frequency meter
Answer: C

Q208. PMMC stands for
A) Permanent Magnet Moving Coil
B) Permanent Magnet Metal Coil
C) Parallel Magnet Moving Coil
D) Permanent Magnetic Multimeter Coil
Answer: A

Q209. PMMC instruments are used for
A) DC only
B) AC only
C) Both AC and DC
D) None
Answer: A

Q210. Moving Iron instruments are used for
A) AC only
B) DC only
C) Both AC and DC
D) None
Answer: C

Q211. The deflecting torque in PMMC instrument is proportional to
A) I
B) I²
C) V²
D) 1/I
Answer: A

Q212. The control torque in PMMC is provided by
A) Springs
B) Gravity
C) Magnetic field
D) Pointer
Answer: A

Q213. The damping torque in PMMC is produced by
A) Eddy currents
B) Air friction
C) Fluid pressure
D) Spring
Answer: A

Q214. The scale of PMMC instrument is
A) Uniform
B) Non-uniform
C) Logarithmic
D) Circular
Answer: A

Q215. The scale of a Moving Iron instrument is
A) Non-uniform
B) Uniform
C) Linear
D) Logarithmic
Answer: A

Q216. The main disadvantage of PMMC is
A) Can’t be used for AC
B) Expensive
C) Heavy
D) Non-linear scale
Answer: A

Q217. A voltmeter is always connected
A) In series
B) In parallel
C) Across source
D) To earth
Answer: B

Q218. An ammeter is always connected
A) In parallel
B) In series
C) Across load
D) To neutral
Answer: B

Q219. The internal resistance of a voltmeter is
A) High
B) Low
C) Zero
D) Medium
Answer: A

Q220. The internal resistance of an ammeter is
A) High
B) Low
C) Medium
D) Very high
Answer: B

Q221. The ohmmeter contains
A) Battery
B) Voltmeter
C) Ammeter
D) All of these
Answer: D

Q222. The wattmeter measures
A) Energy
B) Power
C) Current
D) Resistance
Answer: B

Q223. The energy meter measures
A) Power
B) Energy
C) Voltage
D) Frequency
Answer: B

Q224. The unit of electric energy is
A) kWh
B) kVA
C) kVAR
D) Amp-hour
Answer: A

Q225. 1 kWh =
A) 3600 J
B) 3.6 × 10⁶ J
C) 360 J
D) 3.6 × 10³ J
Answer: B

Q226. 1 horsepower =
A) 736 W
B) 1000 W
C) 746 W
D) 700 W
Answer: C

Q227. The basic principle of measurement is
A) Comparison
B) Calculation
C) Conversion
D) None
Answer: A

Q228. An instrument that measures without drawing power is
A) Null type
B) Deflection type
C) Indicating
D) Recording
Answer: A

Q229. The term “accuracy” means
A) Closeness to true value
B) Repeatability
C) Resolution
D) Error-free
Answer: A

Q230. The term “precision” means
A) Repeatability of measurements
B) Closeness to standard
C) Zero error
D) Linearity
Answer: A

Q231. One milliampere equals
A) 0.1 A
B) 0.01 A
C) 0.001 A
D) 0.0001 A
Answer: C

Q232. One kilovolt equals
A) 100 V
B) 1000 V
C) 10 V
D) 10,000 V
Answer: B

Q233. One megaohm =
A) 10³ Ω
B) 10⁶ Ω
C) 10⁹ Ω
D) 10¹² Ω
Answer: B

Q234. The SI unit of frequency is
A) Hertz
B) Radian
C) Cycle
D) Second
Answer: A

Q235. The SI unit of charge is
A) Coulomb
B) Ampere
C) Volt
D) Joule
Answer: A

Q236. A multimeter can measure
A) Voltage
B) Current
C) Resistance
D) All of these
Answer: D

Q237. A megger is used to measure
A) Insulation resistance
B) Low resistance
C) Current
D) Power
Answer: A

Q238. The instrument used to measure speed is
A) Tachometer
B) Wattmeter
C) Galvanometer
D) Energy meter
Answer: A

Q239. The galvanometer measures
A) Small current
B) Voltage
C) Power
D) Resistance
Answer: A

Q240. The pointer of a meter is made light to
A) Reduce inertia
B) Reduce torque
C) Increase friction
D) Increase accuracy
Answer: A

Q241. An ammeter coil should have
A) Low resistance
B) High resistance
C) Medium resistance
D) None
Answer: A

Q242. A voltmeter coil should have
A) High resistance
B) Low resistance
C) Medium resistance
D) None
Answer: A

Q243. Deflection torque acts
A) To move pointer
B) To oppose motion
C) To control speed
D) To damp oscillation
Answer: A

Q244. Control torque acts
A) To bring pointer back to zero
B) To cause deflection
C) To increase sensitivity
D) To reduce error
Answer: A

Q245. Damping torque acts
A) To stop oscillation
B) To cause deflection
C) To provide restoring torque
D) None
Answer: A

Q246. The time base in CRO produces
A) Sawtooth voltage
B) Sine wave
C) Square wave
D) Triangular wave
Answer: A

Q247. A CRO can measure
A) Voltage
B) Frequency
C) Phase
D) All of these
Answer: D

Q248. LVDT is used to measure
A) Displacement
B) Current
C) Voltage
D) Power
Answer: A

Q249. Thermocouple measures
A) Temperature
B) Pressure
C) Humidity
D) Flow
Answer: A

Q250. A strain gauge measures
A) Strain
B) Temperature
C) Voltage
D) Pressure
Answer: A

Q251. In a Wheatstone bridge, the unknown resistance is found by
A) Balancing condition
B) Deflection
C) Magnetic field
D) None
Answer: A

Q252. The bridge used for inductance measurement is
A) Maxwell bridge
B) Schering bridge
C) Wheatstone bridge
D) Kelvin bridge
Answer: A

Q253. The Schering bridge measures
A) Capacitance
B) Resistance
C) Inductance
D) Frequency
Answer: A

Q254. A Kelvin double bridge measures
A) Low resistance
B) High resistance
C) Medium resistance
D) Capacitance
Answer: A

Q255. The standard resistor is used for
A) Calibration
B) Power measurement
C) Energy measurement
D) None
Answer: A

Q256. The term “span” means
A) Range of measurement
B) Accuracy
C) Resolution
D) Frequency limit
Answer: A

Q257. The resolution of an instrument means
A) Smallest change it can detect
B) Accuracy
C) Repeatability
D) Error
Answer: A

Q258. 1 ohm =
A) 1 V / 1 A
B) 1 A / 1 V
C) 1 W / 1 A
D) 1 A × 1 V
Answer: A

Q259. A potentiometer measures
A) Voltage accurately
B) Current
C) Power
D) Resistance
Answer: A

Q260. The term “calibration” means
A) Comparing with standard
B) Adjusting zero
C) Cleaning
D) Replacement
Answer: A

Q261. An analog instrument displays output using
A) Pointer
B) Numbers
C) Display screen
D) LED
Answer: A

Q262. A digital instrument displays output using
A) Numeric display
B) Pointer
C) Dial
D) Scale
Answer: A

Q263. The pointer should be read at
A) Eye level
B) Any angle
C) Top view
D) Bottom view
Answer: A

Q264. Parallax error occurs due to
A) Improper viewing angle
B) Calibration
C) Friction
D) Temperature
Answer: A

Q265. A mirror is provided behind pointer to
A) Avoid parallax error
B) Increase accuracy
C) Decorate dial
D) None
Answer: A

Q266. The function of fuse in instrument is
A) Protection
B) Damping
C) Control
D) Measurement
Answer: A

Q267. The error caused by external magnetic field can be reduced by
A) Magnetic shielding
B) Large case
C) Small pointer
D) Thick coil
Answer: A

Q268. The extension of voltmeter range is done using
A) Multiplier
B) Shunt
C) Coil
D) Bridge
Answer: A

Q269. The extension of ammeter range is done using
A) Shunt
B) Multiplier
C) Capacitor
D) Resistor
Answer: A

Q270. The sensitivity of voltmeter =
A) 1 / (Full-scale current)
B) 1 / (Resistance)
C) V / I
D) None
Answer: A

Q271. A galvanometer can be converted to ammeter by adding
A) Shunt
B) Multiplier
C) Resistor in series
D) Capacitor
Answer: A

Q272. A galvanometer can be converted to voltmeter by adding
A) Multiplier
B) Shunt
C) Capacitor
D) Diode
Answer: A

Q273. A rectifier converts
A) AC to DC
B) DC to AC
C) High voltage to low
D) None
Answer: A

Q274. The heating effect of current is used in
A) Hot wire instrument
B) PMMC
C) Moving iron
D) Electrostatic
Answer: A

Q275. The electrostatic instrument measures
A) High voltage
B) Low voltage
C) Current
D) Power
Answer: A

Q276. The hot wire instrument is suitable for
A) AC and DC
B) DC only
C) AC only
D) None
Answer: A

Q277. A synchroscope is used to measure
A) Phase difference between voltages
B) Resistance
C) Frequency
D) Power
Answer: A

Q278. A frequency meter measures
A) Frequency
B) Voltage
C) Power
D) Current
Answer: A

Q279. A clamp meter measures
A) Current without breaking circuit
B) Voltage
C) Resistance
D) Power
Answer: A

Q280. The load on an instrument should be
A) Minimum
B) Maximum
C) Equal to rated
D) None
Answer: A

Q281. The unit of inductance is
A) Henry
B) Tesla
C) Weber
D) Ohm
Answer: A

Q282. The unit of capacitance is
A) Farad
B) Ohm
C) Volt
D) Henry
Answer: A

Q283. The instrument for AC/DC power measurement is
A) Dynamometer wattmeter
B) PMMC
C) Electrostatic
D) Hot wire
Answer: A

Q284. The magnetic effect of current is used in
A) MI instrument
B) PMMC
C) Both A and B
D) None
Answer: C

Q285. The voltage sensitivity is
A) Deflection per volt
B) Volt per deflection
C) Ampere per volt
D) Volt per ohm
Answer: A

Q286. An instrument’s “loading effect” is due to
A) Power absorbed by instrument
B) Coil friction
C) Magnetic field
D) Temperature
Answer: A

Q287. A bridge is said to be balanced when
A) Galvanometer shows zero
B) Shows maximum deflection
C) Shows partial deflection
D) None
Answer: A

Q288. In a 3-phase power measurement by two wattmeter method, if readings are equal, the power factor is
A) Unity
B) 0
C) 0.5
D) 0.866
Answer: A

Q289. In the same method, if one wattmeter reads zero, pf =
A) 0.5
B) 0.866
C) 0
D) 0.707
Answer: B

Q290. If both wattmeters read equal and opposite, pf =
A) 0
B) 1
C) 0.5
D) 0.866
Answer: A

Q291. The deflection torque in a wattmeter is proportional to
A) VIcosφ
B) VI
C) V/I
D) I²
Answer: A

Q292. The torque constant in PMMC depends on
A) Spring stiffness
B) Magnetic flux
C) Both A & B
D) None
Answer: C

Q293. The sensitivity of a galvanometer is increased by
A) Stronger magnet
B) Long pointer
C) Light coil
D) All
Answer: D

Q294. An analog meter’s full-scale reading corresponds to
A) Maximum current
B) Minimum current
C) Average current
D) None
Answer: A

Q295. A moving coil instrument has which damping?
A) Eddy current
B) Air friction
C) Fluid friction
D) Magnetic
Answer: A

Q296. The temperature error in resistance measurement can be minimized using
A) Material with low temp coefficient
B) Large current
C) Long wire
D) None
Answer: A

Q297. A CRO uses
A) Cathode ray tube
B) Multimeter
C) Coil
D) Resistor
Answer: A

Q298. The brightness in CRO depends on
A) Beam current
B) Sweep
C) Frequency
D) Deflection
Answer: A

Q299. The spot on CRO screen is deflected horizontally by
A) Time base
B) Vertical amplifier
C) Deflection plates
D) Power supply
Answer: A

Q300. The spot on CRO screen is deflected vertically by
A) Input signal
B) Sweep voltage
C) DC bias
D) None
Answer: A