(b) Lead
   (c) Nickel
   (d) An alloy of tin and lead
Ans: (d)
280. No current will flow between two charged bodies if they have the same
   (a) resistance
   (b) charge
   (c) potential
   (d) charge/potential ratio
Ans: (c)
281. A ruse wire is characterised by
   (a) high resistance and high melting point
   (b) high resistance and low melting point
   (c) low resistance and high melting point
   (d) low resistance and low melting point
Ans: (d)
282. In a microphone
   (a) sound energy is converted into electrical energy
   (b) electrical energy is converted into sound energy
   (c) sound energy is converted into mechanical energy
   (d) mechanical energy is converted into sound energy
Ans: (a)
283. An ohm is a unit of
   (a) potential difference
   (b) resistance
   (c) current
   (d) All the above
Ans: (b)
284. A wire conveying a current deflects a pivoted magnetic needle. This was
   discovered by
   (a) Marconi
   (b) Oersted
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