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101. These instruments are generally named after the electrical quantity to be measured.

102. One in which the magnitude of the measured quantity is indicated by means of a pointer. Ans. analog

103. Indicating Instruments indicates directly the value of the quantity being measured on the scale.

104. Integrating Instruments is a combination of two or more electrical quantities and registers it as a single equivalent unit.

105. Recording Instruments give a continuous record of variations of the electrical quantity being measured over a selected period of time.

106. Three distinct forces are essential for the satisfactory indicating of the pointer on a dial: deflecting torque ,damping torque,controllingtorque

107. Operating Torque is the torque which deflects the pointer on a calibrated scale according to the electrical quantity passing through theinstrument.

108. The torque which controls the movement of the pointer on a particular scale according to the quantity of electricity passing through it is arestoring torque

109. The torque which avoids the vibration of the pointer on a particular range of scale, such a damping or stabilizing force is necessary to bring thepointer to rest quickly, otherwise, due to inertia of the moving system, the pointer will oscillate about its final deflected position for quite some timebefore coming to rest in the steady position.

110. Aside from resistance, what other measurement can an ohmmeter make? Ans.: circuit continuity

111. How is a series-type ohmmeter connected to the circuit being measured?Ans.: The ohmmeter is connected in series with the resistance to be measured.

112. Controlling Instruments are widely used in industrial processes. Their function is to control the quantity being measured with the help ofinformation fed back to them by monitoring devices. This employed in science and industry.

113. Which is not essential for the working of an indicating instrument? Ans.: Braking torque

114. Series and shunt are the two types of ohmmeters.

115. What is the most obvious difference between the two types of ohmmeters?

Ans.: Series ohmmeters have 0 on the right end of the scale and infinity on the left end of the scale. Shunt ohmmeters are the opposite

116. What is the primary use of a megger? Ans.: To measure high resistance

117. The procedure for using a megger to check the insulation of a conductor are:I. Connect one lead to the insulation and one lead to the conductor.II. Turn the hand crank until it starts to slip.

118. Infinity is the normal indication on a megger when checking insulation?

119. Why is the dc scale on a multimeter different than the ac scale?Ans.: The meter movement reacts to average ac voltage and current and the effective value is desired

120. To stop parallax erroris the reason for having a mirror on the scale of a multimeter.

121. How is the mirror on a multimeter used?

Ans.: Make sure no image of the pointer is visible in the mirror when reading the meter

122. Why would you use a hook-on voltameter instead of a multimeter?

Ans.: To measure current safely and easily (with no need to disconnect the wiring of the circuit).

123. Growleris a device used to test the armatures and stators of electric motor, generators and other equipment for short circuit.

124. A WATT-HOUR METER is basically a small motor whose instantaneous speed is proportional to the power through the motor

125. Vibrating reed and moving disk are two types of frequency meters.

126. The vibrating-reed frequency meter is one of the simplest devices for indicating the frequency of an AC source. They are used on powerpanels to monitor the frequency of ac.

127. Moving-disk frequency meters are most commonly out-of-circuit meters. They can be used to spot check the frequency of power sources orequipment signals.

128. Moving Iron instruments depend for their action upon the magnetic effect of current, and are widely used as indicating instruments.

129. There are two basic forms of moving iron instruments: Attraction type and Repulsion type

130. Repulsion type consists of a fixed coil inside which two soft -iron and are arranged parallel to one another and along the axis of the coil.

131. Electrodynamometer meters have low sensitivity and high accuracy.

132. PMMC meter movements are the most sensitive.

133. PMMC meter movements cannot directly measure AC.

134. Electrodynamometermeter movement is used to measure power.

135. PMMC meter movement uses a permanent magnet

136. Electrodynamometermeter movement uses a moving coil and a fixed coil?

137. The induction type wattmeter can be used to measure AC power only in contrast to dynamometer wattmeter which can be used to measureDC as well as AC power.

138. Clamp meters are a very convenient testing instrument that permits current measurements on a live conductor without circuit interruption.

139. Gross Errors are largely human errors, among them are misreading of instruments, incorrect adjustment and improper application ofinstruments and computational mistakes.

140. Systematic Errors are errors due to shortcomings of the instruments, such as defective or worm parts and effects of the environmental on the

equipment.

141. Random Errors: are errors due to cause that cannot be directly established because of random variations in the parameter or the system ofmeasurement.

142. One common gross error, frequently committed by beginners in measurement work, involves the improper use of an instrument.

143. Misreading Errors are gross errors that the operator may misread a value or a scale.

144. Calculation Errors are gross errors that the operator may make a mistake in carrying out a calculation.

145. Incorrect Instrument occurs when the operator may choose the wrong instrument or measurement method and so obtain incorrect results.

146. Incorrect Adjustment occurs when the operator may incorrectly adjust some aspect of the measurement system, e.g., incorrectly set thebalance condition with a bridge or set the zero on a galvanometer.

146. Environmental errors are due to external conditions affecting the measurement.

147. Instrumental errors are errors inherent in measuring instruments because of their mechanical structure.

148. Instrumental errors may be avoided by following these guidelines:Selecting a suitable instrument for the particular measurement applications

Applying correction factors after determining the amount of instrumental error

Calibrating the instrument against a standard .

149. Environmental errors are due to conditions external to the measuring device, including conditions in the area surrounding the instrument, such

as the effects of changes in temperature, humidity, barometric pressure, or of magnetic or electrostatic fields.

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150. Random errors are errors due to unknown causes and occur even when all systematic errors have been accounted for.

151. Operating Errors are errors that arise because an operator is taking the measurement. They are not mistakes but errors due to situations thatlead to small variations in the readings perceived by operators.

152. They include the errors in reading the position of a pointer a scale, due to the scale and pointer not being in the same plane, the readingobtained then depending on the angle at which the pointer is viewed against the scale, the so called parallax error.

153. Circuit components such as capacitors, resistors, etc. are guaranteed within a certain percentage of their rated value. The limits of thesedeviations from the specified values are known as limiting errors or guarantee errors.

154. Among the multimeters, the VOM features compactness, simplicity and portability.

155. Dynamometeris a device used to measure the mechanical output of a motor or a generator is called__________a. watt-hour meter c. engine indicatorb. sphygmomanometer d. dynamometer

156.Hydrometeris an instrument used to measure specific gravity of the liquid in a storage battery.

157. The following are common sources of systematic error: construction errors, ageing errors, and loading errors

158. Construction Errors are errors resulting from the manufacture of an instrument and the components used. They arise from such causes astolerances on the dimensions of components and on the values of electrical components used.

159. Ageing Errors are errors resulting from instruments getting older, e.g., bearings wearing, components deteriorating and their values changing,a build-up of deposits on surfaces affecting content resistances and insulation.

160. Insertion or Loading Errors are errors introduced into the measurement when an instrument is connected into a circuit. For example,inserting an ammeter into a circuit to measure a current changes the value of the current due to the ammeters own resistance .

161. The part of the instrument used to select the particular electrical quantity to be measure is the function switch.

162. The multimeter is not capable of measuring AC amperes.

163. To make a voltage measurement, which control would be set in a voltage position? Ans.: function

164. Voltmeter is used to measure the difference of potential or electrical pressure or voltage drop between two points in a circuit.

165. Voltmeteris essentially an ammeter and resistance connected in series, and when connected across a voltage source current flows throughresistance and the meter.

166. Kilo-voltmeteris a voltmeter used to measure voltages higher than 1000 volts.

167. Vacuum-tube voltmeteris an electronic voltmeter that utilizes one or more vacuum tubes for measuring voltage values.

168. The chief advantage of VTVM is that the reading is more accurate compared to that of an ordinary multimeter.

169. Ammeteris to be used when the circuit is broken or cut and it is inserted in series with the circuit under test.

170. Moving iron meter movement is characterized when soft iron bars are placed inside an energized electromagnetic coil; these two bars repeleach other.

171. Radial vane type, concentric vane type and plunger type are three types of moving iron meter.

172. Radial vane type consists of two rectangular pieces of soft iron called vanes surrounded by a coil, one vane is fixed and the other is free torotate.

173. Concentric vane type operates similarly to radial vane meter movement. The only difference between two meters is the shape of the vanesand their position with respect to each other.

174. The vanes are semi-circular in shape and one of it is placed is placed parallel to the other vane is a concentric vane type

175. The plunger type meter movement consists of a movable soft iron core placed partially within a fixed coil.

176. Thermal current meteris a type of meter makes use of heat produced by the current flow to measure the amount of current flow.

177. Thermocouple meteris a type of meter is a combination of hot wire ammeter and moving coil meter with a device known as thermocoupleadded.

178. AC meters are classified as sine wave instrument

179. Kilo-ammeteris a current meter which is used to measure very high amount of current.

180. Current transformeris an instrument transformer whose function is to step down/decrease the available very high current to a small one.

181. A clamp-on ammeter consists of an iron core with a coil wound on it and an an ordinary current meter

182. Megger is also known as insulation resistance tester

183. Ammeter shunts are used to extend the range of an ammeter.

184. Potential divideris used to extend the range of voltmeter

185. Photometeris an instrument used to measure luminous intensity of light.

186. An oscilloscope is used to measure maximum voltage

187. When using any electrical instruments to test or troubleshoot an electrical circuit, an electrician should consider first his personal safety beforeanything else _

188. The minimum number of wattmeters necessary to measure the power in the load of a balanced 3-phase, 4-wire system is one

189. A VTVM is more reliable on measuring voltages across low impedance as compared to a multitester because of its sensitivity, it offers highinput impedance and it does not alter the measured voltage

190. The value of the voltage that is indicated on an AC voltmeter is called effective value

191. Induction type single phase meter is a true watt-hour meter

192. An AC ammeter or voltmeter is calibrated to read rms values, this means the meter is reading the effective value.

193. A megger is always used on a de-energized circuit

194. A power factor meter will show relationship between watts and volt-amperes

195. Dial indicatoris an instrument used to check the motor shaft alignment.

196. In the absence of a voltmeter, oscilloscope is an instruments used to measure potential difference.

197. Kilowatt-hour meteris an instrument used to measure electrical energy.

198. Where does the power supply for a megger come from? Ans.: a hand driven generator

199. A wattmeter indicates real power

200. Thermocouple type ammeter is preferable for high frequency current measurements