Q.81)-The metal whose electrical conductivity is more, is
  • Copper
  • Aluminium
  • Silver
  • Lead
Q.82)-Moving electric charge produces;
  • Magnetic field
  • Sound waves
  • Light rays
  • Heat waves
Q.83)-Safety fuse wire used in domestic electrical appliances is made of metal of low
  • Resistance
  • Melting point
  • Specific gravity
  • Conductance
Q.84)-A fuse wire is made of
  • An alloy of tin and copper
  • An alloy of tin and lead
  • An alloy of tin and aluminium
  • An alloy of nickel and chrominum
Q.85)-A transformer works with
  • Alternating current only
  • Direct current only
  • Both AC and DC
  • Any signal
Q.86)-Which of the following is a good conductor of heat
  • Mica
  • Asbestos
  • Celluloid
  • Paraffin wax
Q.87)-For which of the following substances, the resistance decreases with iccreases in temperature?
  • Pure silicon
  • Copper
  • Nichrome
  • Platinum
Q.88)-Indicate the false statement about the resistance of wire
  • It depends upon the material of wire
  • It is directly proportional to the length of wire
  • It is directly proportional to the area of cross-section of wire
  • Resistance of metallic wire increases with increase in temperature
Q.89)-Farad' is the unit of
  • Capacitance
  • Inductance
  • Resistance
  • Conductance
Q.90)-Ohm's law is valid in case of
  • Semiconductor
  • Conductor
  • Superconductor
  • Insulator