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