(a) Silver
   (b) Copper
   (c) Nichrome
   (d) Dry wood
Ans: (d)
250. A rod of brass is held in hand and rubbed with fur. The rod is found to
   (a) no charge
   (b) positive charge
   (c) negative charge
   (d) can"t be said
Ans: (a)
251. For detecting and, testing of small electric charges we use
   (a) an electrophorus
   (b) an electroscope
   (c) an electromagnet
   (d) an ammeter
Ans: (b)
252. A lightning conductor installed in a building
   (a) does not allow the lightning to fall on the building at all
   (b) drives away the charged clouds
   (c) forces the lightning to fall on other buildings near that building
   (d) conducts the electric charges to the ground when lightning strikes the
Ans: (d)
253. An electric charge is measured in
   (a) coulomb
   (b) ampere
   (c) volt
   (d) watt
Ans: (a)