Aluminium
Paper
Rubber
Mica
Answer is Right!
Answer is Wrong!
Detailed SolutionWhich one of the following does not have negative temperature coefficient?
Current electricity
22. Copper wire of certain length and resistance is drawn out to three times its length without change in volume, the new resistance of wire becomes
$$ rac{1}{9}$$ times
3 times
9 times
Unchanged
Answer is Right!
Answer is Wrong!
23. Electric pressure is also called
Resistance
Power
Voltage
Energy
Answer is Right!
Answer is Wrong!
24. The filament of an electric bulb is made of
Carbon
Aluminium
Tungsten
Nickel
Answer is Right!
Answer is Wrong!
Detailed SolutionThe filament of an electric bulb is made of
25. Three 60 W bulbs are in parallel across the 60 V power line. If one bulb burns open
There will be heavy current in the main line
Rest of the two bulbs will not light
All three bulbs will light
The other two bulbs will light
Answer is Right!
Answer is Wrong!
Detailed SolutionThree 60 W bulbs are in parallel across the 60 V power line. If one bulb burns open
26. Which method can be used for absolute measurement of resistances?
Lorentz method
Raleigh method
Ohm's law method
Wheatstone bridge method
Answer is Right!
Answer is Wrong!
Detailed SolutionWhich method can be used for absolute measurement of resistances?
27. Insulating materials have the function of
Preventing a short circuit between conducting wires
Preventing an open circuit between the voltage source and the load
Conducting very large currents
Storing very high currents
Answer is Right!
Answer is Wrong!
28. Bulbs in street lighting are all connected in
Parallel
Series
Series-parallel
End-to-end
Answer is Right!
Answer is Wrong!
Detailed SolutionBulbs in street lighting are all connected in
29. Voltage dependent resistors are used
For inductive circuits
To suppress surges
As heating elements
As current stabilizers
Answer is Right!
Answer is Wrong!
30. With rise in temperature the resistance of pure metals
Increases
Decreases
First increases and then decreases
Remains constant
Answer is Right!
Answer is Wrong!
Detailed SolutionWith rise in temperature the resistance of pure metals