A galvanometer can be converted into an ammeter by connecting

 

ELECTRICAL AND ELECTRONIC MEASUREMENTS MCQs 

Q101. A galvanometer can be converted into an ammeter by connecting
A) A low resistance in parallel
B) A high resistance in series
C) A low resistance in series
D) A capacitor in parallel
Answer: A

Q102. A galvanometer can be converted into a voltmeter by connecting
A) A high resistance in series
B) A low resistance in parallel
C) A high resistance in parallel
D) No resistance
Answer: A

Q103. The damping torque in moving coil instruments is produced by
A) Eddy currents
B) Gravity
C) Spring
D) Friction
Answer: A

Q104. The controlling torque in a moving coil instrument is provided by
A) Spring
B) Weight
C) Magnet
D) Pointer
Answer: A

Q105. The main function of a shunt in an ammeter is to
A) Bypass most of the current
B) Increase resistance
C) Provide damping
D) Measure voltage
Answer: A

Q106. The range of a voltmeter can be increased by using a
A) Multiplier
B) Shunt
C) Capacitor
D) Transformer
Answer: A

Q107. The unit of resistance is
A) Ohm
B) Volt
C) Ampere
D) Farad
Answer: A

Q108. The unit of current is
A) Ampere
B) Volt
C) Watt
D) Coulomb
Answer: A

Q109. The unit of electric charge is
A) Coulomb
B) Volt
C) Farad
D) Ampere
Answer: A

Q110. The unit of power is
A) Watt
B) Volt
C) Ampere
D) Joule
Answer: A

Q111. A wattmeter measures
A) Power
B) Voltage
C) Current
D) Energy
Answer: A

Q112. The unit of energy is
A) Joule
B) Watt
C) Volt
D) Henry
Answer: A

Q113. An energy meter measures
A) Energy consumed
B) Power
C) Voltage
D) Frequency
Answer: A

Q114. A voltmeter is always connected
A) In parallel
B) In series
C) Across supply
D) Both A and C
Answer: D

Q115. An ammeter is connected
A) In series
B) In parallel
C) Across supply
D) None
Answer: A

Q116. A moving iron instrument works on
A) Magnetic attraction or repulsion
B) Heating effect
C) Electromagnetic induction
D) Chemical effect
Answer: A

Q117. A PMMC instrument works on
A) Motor principle
B) Heating principle
C) Induction principle
D) Repulsion principle
Answer: A

Q118. A CRO displays
A) Waveforms
B) Voltage only
C) Frequency only
D) Current
Answer: A

Q119. In a CRO, X-axis represents
A) Time
B) Voltage
C) Current
D) Power
Answer: A

Q120. In a CRO, Y-axis represents
A) Voltage
B) Current
C) Frequency
D) Power
Answer: A

Q121. The instrument used for measuring resistance is
A) Ohmmeter
B) Wattmeter
C) Ammeter
D) Voltmeter
Answer: A

Q122. The instrument used for measuring voltage is
A) Voltmeter
B) Ammeter
C) Wattmeter
D) Energy meter
Answer: A

Q123. The instrument used for measuring current is
A) Ammeter
B) Voltmeter
C) Wattmeter
D) Frequency meter
Answer: A

Q124. The meter used to measure electrical energy consumed is
A) Energy meter
B) Wattmeter
C) Voltmeter
D) Ammeter
Answer: A

Q125. 1 kWh =
A) 3.6 × 10⁶ J
B) 3600 J
C) 36 × 10⁶ J
D) 360 J
Answer: A

Q126. The term “range” of an instrument means
A) Maximum value it can measure
B) Minimum value
C) Average value
D) Constant value
Answer: A

Q127. The term “accuracy” means
A) Closeness to true value
B) Repeatability
C) Resolution
D) Error
Answer: A

Q128. The term “precision” means
A) Repeatability of results
B) Closeness to true value
C) Least error
D) Range
Answer: A

Q129. The term “sensitivity” means
A) Ratio of output to input
B) Repeatability
C) Range of measurement
D) None
Answer: A

Q130. The instrument which shows instantaneous value is
A) Indicating type
B) Recording type
C) Integrating type
D) Digital type
Answer: A

Q131. The instrument which records continuously is
A) Recording type
B) Integrating type
C) Indicating type
D) None
Answer: A

Q132. The instrument which measures total quantity over time is
A) Integrating type
B) Recording type
C) Indicating type
D) Null type
Answer: A

Q133. Example of integrating type instrument is
A) Energy meter
B) Ammeter
C) Voltmeter
D) Wattmeter
Answer: A

Q134. The damping torque helps to
A) Bring the pointer quickly to rest
B) Provide deflection
C) Increase oscillations
D) Decrease sensitivity
Answer: A

Q135. The deflecting torque in an instrument is produced by
A) Current
B) Voltage
C) Both
D) Power
Answer: A

Q136. The purpose of control torque is to
A) Provide restoring force
B) Produce deflection
C) Reduce oscillations
D) Increase range
Answer: A

Q137. The controlling torque is absent in
A) Ballistic galvanometer
B) PMMC
C) MI instrument
D) Wattmeter
Answer: A

Q138. For AC measurement, which instrument can be used?
A) Moving Iron
B) PMMC
C) Both
D) None
Answer: A

Q139. The power factor of a purely resistive circuit is
A) 1
B) 0
C) 0.5
D) -1
Answer: A

Q140. The power factor of a purely inductive circuit is
A) 0
B) 1
C) 0.5
D) -1
Answer: A

Q141. The wattmeter has
A) Two coils
B) One coil
C) Three coils
D) Four coils
Answer: A

Q142. The current coil of wattmeter carries
A) Line current
B) Voltage
C) Power
D) None
Answer: A

Q143. The pressure coil of wattmeter carries
A) Voltage
B) Current
C) Power
D) Energy
Answer: A

Q144. The symbol for voltmeter is represented by
A) V inside a circle
B) A inside a circle
C) W inside a circle
D) E inside a circle
Answer: A

Q145. The symbol for ammeter is represented by
A) A inside a circle
B) V inside a circle
C) W inside a circle
D) None
Answer: A

Q146. The symbol for wattmeter is represented by
A) W inside a circle
B) V inside a circle
C) A inside a circle
D) None
Answer: A

Q147. The unit of inductance is
A) Henry
B) Farad
C) Ohm
D) Volt
Answer: A

Q148. The unit of capacitance is
A) Farad
B) Henry
C) Ohm
D) Volt
Answer: A

Q149. 1 Farad =
A) 1 Coulomb/Volt
B) 1 Volt/Coulomb
C) 1 Ampere/Volt
D) 1 Watt/Volt
Answer: A

Q150. The range of a galvanometer is limited because
A) Coil may get damaged at high current
B) Pointer friction
C) Large scale
D) High resistance
Answer: A

Q151. A galvanometer shows full-scale deflection for 10 mA current. To measure 1A, the required shunt resistance is
A) Very small
B) Very large
C) Infinite
D) None
Answer: A

Q152. A galvanometer has 100Ω resistance. To convert it into a 10V voltmeter, series resistance required for 1mA full-scale is
A) 9.9 kΩ
B) 9 kΩ
C) 100Ω
D) 1Ω
Answer: A

Q153. The ratio of true value to measured value is called
A) Accuracy
B) Sensitivity
C) Precision
D) None
Answer: A

Q154. The bridge used to measure unknown resistance is
A) Wheatstone bridge
B) Maxwell bridge
C) Schering bridge
D) Wien bridge
Answer: A

Q155. In Wheatstone bridge, at balance point
A) No current flows through galvanometer
B) Maximum current flows
C) Voltage is zero
D) None
Answer: A

Q156. The potentiometer measures EMF more accurately than a voltmeter because
A) No current flows through the source
B) High resistance used
C) Magnetic damping used
D) None
Answer: A

Q157. The instrument used to measure frequency is
A) Frequency meter
B) Wattmeter
C) Ammeter
D) Energy meter
Answer: A

Q158. The instrument used to measure power factor is
A) Power factor meter
B) Wattmeter
C) Voltmeter
D) Energy meter
Answer: A

Q159. A multimeter can measure
A) Voltage, Current, and Resistance
B) Only current
C) Only voltage
D) Only resistance
Answer: A

Q160. The function of fuse is to
A) Protect the circuit from overcurrent
B) Increase voltage
C) Measure current
D) Store energy
Answer: A

Q161. The type of error caused by parallax is
A) Observational error
B) Instrumental error
C) Environmental error
D) None
Answer: A

Q162. The ammeter should have
A) Low resistance
B) High resistance
C) Medium resistance
D) None
Answer: A

Q163. The voltmeter should have
A) High resistance
B) Low resistance
C) Medium resistance
D) None
Answer: A

Q164. The wattmeter is connected
A) Pressure coil in parallel, current coil in series
B) Both in series
C) Both in parallel
D) None
Answer: A

Q165. A megger is used to measure
A) Insulation resistance
B) Capacitance
C) Power
D) Frequency
Answer: A

Q166. A galvanometer is used to detect
A) Small current
B) Large current
C) Voltage
D) Power
Answer: A

Q167. A digital multimeter gives output in
A) Numerical form
B) Analog form
C) Mechanical form
D) None
Answer: A

Q168. A CRO is also called
A) Oscilloscope
B) Voltmeter
C) Ammeter
D) Wattmeter
Answer: A

Q169. The number of divisions between two time marks on CRO gives
A) Time period
B) Frequency
C) Voltage
D) Power
Answer: A

Q170. Frequency = 1 / Time period
A) True
B) False
Answer: A

Q171. A potentiometer works on the principle of
A) Null measurement
B) Deflection method
C) Magnetic effect
D) Heating effect
Answer: A

Q172. The most accurate type of instrument is
A) Null type
B) Deflection type
C) Recording type
D) Digital
Answer: A

Q173. The full form of LVDT is
A) Linear Variable Differential Transformer
B) Linear Variable Directional Transducer
C) Linear Variable DC Transformer
D) None
Answer: A

Q174. The output of a thermocouple is
A) Voltage proportional to temperature difference
B) Current
C) Resistance
D) Power
Answer: A

Q175. The basic unit of electric potential is
A) Volt
B) Ampere
C) Coulomb
D) Watt
Answer: A

Q176. A dynamometer wattmeter can be used for
A) Both AC and DC
B) AC only
C) DC only
D) None
Answer: A

Q177. The PMMC instrument can measure
A) DC only
B) AC only
C) Both
D) None
Answer: A

Q178. The MI instrument can measure
A) Both AC and DC
B) DC only
C) AC only
D) None
Answer: A

Q179. A moving coil instrument has a
A) Uniform scale
B) Non-uniform scale
C) Log scale
D) None
Answer: A

Q180. A moving iron instrument has
A) Non-uniform scale
B) Uniform scale
C) Log scale
D) None
Answer: A

Q181. The temperature coefficient of manganin is
A) Very low
B) High
C) Zero
D) Medium
Answer: A

Q182. The Wheatstone bridge gives maximum sensitivity when
A) All four resistances are of the same order
B) Two resistances are large
C) Two are small
D) Random
Answer: A

Q183. A power factor meter shows
A) Cos φ
B) Tan φ
C) Sin φ
D) φ directly
Answer: A

Q184. The term “form factor” =
A) RMS value / Average value
B) Peak / RMS
C) Average / RMS
D) RMS / Peak
Answer: A

Q185. For a pure sine wave, form factor =
A) 1.11
B) 1
C) 0.707
D) 1.414
Answer: A

Q186. The peak factor =
A) Peak value / RMS value
B) RMS / Peak
C) RMS / Average
D) None
Answer: A

Q187. The wattmeter reading is zero when
A) Voltage and current are 90° out of phase
B) In phase
C) Opposite
D) None
Answer: A

Q188. The main disadvantage of MI instrument is
A) Non-linear scale
B) Heavy
C) Expensive
D) None
Answer: A

Q189. An ammeter reading is less than true current due to
A) Internal resistance
B) Low sensitivity
C) Parallax
D) None
Answer: A

Q190. A voltmeter reading is less than true voltage due to
A) Loading effect
B) High impedance
C) Parallax
D) None
Answer: A

Q191. The moving coil in a PMMC instrument is wound on
A) Aluminum former
B) Iron core
C) Steel ring
D) Plastic
Answer: A

Q192. Damping in PMMC is due to
A) Eddy currents
B) Spring
C) Air friction
D) Pointer
Answer: A

Q193. Control torque in MI instrument is provided by
A) Spring
B) Gravity
C) None
D) Magnetic
Answer: A

Q194. In an energy meter, braking torque is produced by
A) Eddy currents
B) Magnet
C) Spring
D) Pointer
Answer: A

Q195. The driving torque in an energy meter is proportional to
A) Power
B) Voltage
C) Current
D) Energy
Answer: A

Q196. The creeping error in energy meter is reduced by
A) Holes on the disc
B) Adjusting magnet
C) Lubricating bearings
D) Increasing voltage
Answer: A

Q197. The frequency meter works on
A) Electromagnetic resonance principle
B) Magnetic attraction
C) Heating effect
D) Repulsion
Answer: A

Q198. The dynamometer type wattmeter has
A) Fixed and moving coils
B) Only moving coil
C) Only fixed coil
D) None
Answer: A

Q199. The ratio of voltage to current is called
A) Resistance
B) Power
C) Energy
D) Impedance
Answer: A

Q200. 1 kW =
A) 1000 W
B) 100 W
C) 10 W
D) 1 W
Answer: A