Physics addictz

190. The capacitor preferred for high frequency circuits is ?
a. air capacitor b. mica capacitor c. electrolytic capacitor d. none of the above

189. The electrons, in a dielectric, get detached from the atoms under ?
a. high current b. high voltage c. variable current d. breakdown

188. Electric displacement is a ...... quantity ?
a. scalar b. vector c. both of the above d. none of the above

187. The presence of an uncharged conductor near a charged one increases the ?
a. charge of the charged conductor b. capacity of the charged conductor
c. potential of the charged conductor d. all of the above
49. Electric displacement is a ...... quantity ?

186. . Internal heating of a capacitor is usually attributed to ?
a. electron movement b. leakage resistance c. dielectric charge d. plate vibration

185. ln a cable capacitor, voltage gradient is maximum at the surface of the ?
a. earth b. conduction c. sheath d. insulator

184. . Dielectric strength of medium ?
a. increases with rise in temperature b. increases with moisture content c. same d. none

183. Which of the following medium will have highest value of relative permittivity ?
a. Water b. Glass c. Mica d. Paper

182. In order to remove static electricity from machinery ?
a. construct insulated cabins b. insulate the machinery
c. ground the framework d. humidify the surroundings

181. Mica capacitors are characterised by all of the following except ?
a. stable operation b. accurate value c. low leakage reactance d. low losses

180. Which of the following· capacitor is preferred in case of single phase motor ?
a. Mica capacitor b. Paper capacitor c. Electrolytic capacitor d. Ceramic capacitor

179. The bridge used for the measurement of the value of the capacitance is ?
a. Wien's bridge b. Wheatstone bridge c. Schering bridge d. Hay's bridge