Question 1 :
Why is electric power transmitted over long distances at high voltage?<br>

Question 2 :
The resistance of the series combination of two resistances is S. When they are joined in parallel the total resistance is P. If S = nP, then the minimumpossible value of n is

Question 3 :
What is the total resistance when four resistors of $20, 40, 60$, and $80$ respectively are connected in parallel (in ohm)?

Question 4 :
From below which are the applications of heating effect of electric current?<br>

Question 5 :
A resistor connected to a battery is heated due to current through it. Which of the following quantity does not vary?<br>

Question 6 :
An electric bulb of $30\ W$ consumes $0.72$ units of energy in a day. Find the number of hours it is working in a day?

Question 7 :
Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?<br>

Question 8 :
The temperature of a conductor is increased. The product of resistivity and conductivity:<br/>

Question 9 :
Calculate the energy consumed by $2\ kW$ heater used for $1\ hr$ every day in a period of $30\ \text{days}$.

Question 11 :
How much energy in kilowatt hour is consumed in operating ten 50 watt bulbs for 10 hours per day in a month (30 days)

Question 12 :
The lengths of two wires made of same material&#160;are 2m and 1m. Their radii are 1mm and 2mm.&#160;The ratio of their specific resistances is<br/>

Question 13 :
The temperature coefficient of resistance of a wire is $0.00125$ per degree celcius. At $300K$ its resistance is $1$ ohm.The resistance of the wire will be $2$ ohm at following temperature :-<br>

Question 14 :
The work done in carrying in point charge from one point to the another in an electrostatic field depends on the path along which the point charge is carried.<br>

Question 15 :
Which of the following is used for the formation of thermistor?

Question 16 :
An electric lamp is marked 60 W, 230 V. The cost of 1 kilowatt hour of power is Rs 1.25. The cost of using this lamp for 8 hours is

Question 17 :
When a current is passed in a conductor, $3^oC$ rise in temperature is observed. If the strength of current is made thrice, then rise in temperature will approximately be:

Question 19 :
The heat developed in a system is proportional to the current through it. Then

Question 20 :
If the electric current in a lamp decreases by $5\ \%$,then the power output decreases by:<br>

Question 22 :
A voltmeter and an ammeter are connected in series to an ideal cell of emf E. The voltmeter reading is V and the ammeter reading is l<br>

Question 23 :
A material $B$ has twice the specific resistance of $A$. A circular wire made of $B$ has twice the diameter&#160;of a wire made of $A$. Then for the two wires to have&#160;the same resistance, the ratio $l_{B} $ / $l_{A}$&#160;of their&#160;respective lengths must be:

Question 25 :
Heater of an electric kettle is made of a wire of length L and diameter d. It takes 4 minutes to raise the temperature of 0.5 kg water by 40 K. This heater is replaced by a new heater having two wires of the same material, each of length L and diameter 2d. The way these wires are connected is given in the options. How much time in minutes will it take to raise the temperature of the same amount of water by 40 K?