Question 2 :
Electric power is transmitted over long distance through conducting wires of very high voltage, because.

Question 3 :
When cells are connected in series greater emf is obtained in the circuit.

Question 4 :
Kirchhoff's law of junction, $\displaystyle \sum { I } =0$, is based on

Question 6 :
In a potentiometer experiment of a cell of emf 1.25 V gives balancing length of 30 cm. If the cell is replaced by another cell, balancing length is found to be 40 cm. What is the emf of second cell?

Question 7 :
A boy has two spare light bulbs in his drawer. One is marked $240$V and $100$W and the other is marked $240$V and $60$W. He tries to decide which bulb should be used and why??

Question 8 :
The resistance of a bulb filament is $100\Omega$ at a temperature at $100^{o}C$. If its temperature coefficient of resistance be $0.005/^{o}C$, then its resistance will become $200\Omega$ at a temperature of

Question 9 :
In a circuit two or more cells of the same e.m.f. are connected in parallel in order to

Question 10 :
Which pair is not correct for the instrument used in the laboratory and their uses from the following?<br/><table class="wysiwyg-table"><tbody><tr><td></td><td><b>Instrument</b></td><td><b>Uses</b></td></tr><tr><td>(A)</td><td>Voltmeter</td><td>To measure the electric potential difference&#160;</td></tr><tr><td>(B)</td><td>Ammeter</td><td>To measure the electric current</td></tr><tr><td>(C)</td><td>Galvanometer</td><td>To detect the presence of current</td></tr><tr><td>(D)</td><td>Resistor</td><td>To supply the electric energy to circuit</td></tr></tbody></table>

Question 11 :
Assertion: When current through a bulb decreases by 0.5%, the glow of bulb decreases by 1%. Reason: Glow (Power) which is directly proportional to square of current.

Question 12 :
Two 220 volt, 100 watt bulbs are connectedfirst in series and then in parallel. Each timethe combination is connected to a 220 volt a.c.supply line. The power drawn by thecombination in each case respectively will be

Question 13 :
A constant potential difference is applied between the ends of the wire. If the length of the wire is elongated $4$ times, then the drift velocity of electrons will be:<br/>