[amp_mcq option1=”Aluminium” option2=”Paper” option3=”Rubber” option4=”Mica” correct=”option1″]
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
[amp_mcq option1=”$$\frac{1}{9}$$ times” option2=”3 times” option3=”9 times” option4=”Unchanged” correct=”option1″]
23. Electric pressure is also called
[amp_mcq option1=”Resistance” option2=”Power” option3=”Voltage” option4=”Energy” correct=”option3″]
24. The filament of an electric bulb is made of
[amp_mcq option1=”Carbon” option2=”Aluminium” option3=”Tungsten” option4=”Nickel” correct=”option3″]
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
[amp_mcq option1=”There will be heavy current in the main line” option2=”Rest of the two bulbs will not light” option3=”All three bulbs will light” option4=”The other two bulbs will light” correct=”option4″]
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?
[amp_mcq option1=”Lorentz method” option2=”Raleigh method” option3=”Ohm’s law method” option4=”Wheatstone bridge method” correct=”option1″]
Detailed SolutionWhich method can be used for absolute measurement of resistances?
27. Insulating materials have the function of
[amp_mcq option1=”Preventing a short circuit between conducting wires” option2=”Preventing an open circuit between the voltage source and the load” option3=”Conducting very large currents” option4=”Storing very high currents” correct=”option1″]
28. Bulbs in street lighting are all connected in
[amp_mcq option1=”Parallel” option2=”Series” option3=”Series-parallel” option4=”End-to-end” correct=”option1″]
Detailed SolutionBulbs in street lighting are all connected in
29. Voltage dependent resistors are used
[amp_mcq option1=”For inductive circuits” option2=”To suppress surges” option3=”As heating elements” option4=”As current stabilizers” correct=”option1″]
30. With rise in temperature the resistance of pure metals
[amp_mcq option1=”Increases” option2=”Decreases” option3=”First increases and then decreases” option4=”Remains constant” correct=”option1″]
Detailed SolutionWith rise in temperature the resistance of pure metals