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# Physical Science

236)The starting current of an electric motor is ________ the current flowing after the motor reaches its normal running speed.
exactly equal to nearly equal
much greater than less than

237)Energy conversions in loudspeaker are
electrical to mechanical to sound mechanical to electrical to sound
sound to mechanical to electrical mechanical to sound

238)Energy conversions taking place in microphone are
electrical to mechanical to sound sound to electrical to mechanical
sound to mechanical to electrical elsctrical to sound

239)A transformer is used for
generating electricity converting AC to DC
stepping up (or down ) voltage None of these

240)In our houses we get 220V ac. The value 220 represents
effective voltage constant voltage
average voltage peak voltage

241)What is the frequency of ac current we use at houses?
25Hz 50Hz
75Hz 100Hz

242)The advantage of AC over DC current is that
it is free from voltagefluctuations it can be transmitted over long distance with minimum power loss
it contains more electric energy production cost is less

243)The function of fuse in an electrical circuit is
to regulate the flow of current to break the circuit in case of over loading or short circuiting
to avoid electri shocks none of these

244)In an electrical circuit a fuse is connected
in the neutral wire in the live wire
in the earth wire anywhere

245)If a fuse blows frequently, one should
replace it with thick wire replace it thin wire
check for fault in the circuit None of these

246)The material used for a fuse wire should have
high melting point high resistivity
low melting point low ductility

247)One should not connect a number of electrical appliances to the same power socket because
the appliances will not get proper current the appliances will not get proper voltage
this can damage the appliances this can damage the domestic wiring due to overheating

248)An electrical appliance is earthed to
avoid short circuiting prevent electric shock
protect the appliance against any damage reduce consumption

249)The filament of electric bulb is made of