Question 1 :
Constantan wire is used for making standard resistance, because it has

Question 2 :
An electric heater of resistance $6\ \Omega $ is run for $10\ min$&#160;on a line of $120\ V$. The energy&#160;liberated in this period of time is:<br/>

Question 3 :
Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?<br>

Question 4 :
Which is the equivalent resistance when resistors $3 \Omega$ and $6 \Omega$ are in parallel?<br>

Question 5 :
The current in a wire is doubled keeping temperature constant. Which of the following statements is/are wrong?

Question 6 :
Two resistance thermometers are made, one of the platinum wire and the other of germanium wire. The resistance of both the thermometers are equal at room temperatures. Now the two resistance wires are connected to a battery. The two resistance wire are&#160;heated to 100$^0$C. The potential drop in the two resistance is measured. Which of the following statements is correct?&#160;

Question 7 :
The cells are joined in parallel to get the maximum current when

Question 8 :
From below which are the applications of heating effect of electric current?<br>

Question 9 :
Mark the correctreason why tungsten is used for making filament of electric lamp.

Question 10 :
A typical thermistor can easily measure a change in temperature of the order of

Question 12 :
A current $i$ passes through a wire of length $L$, radius $R$ and resistively $\rho$. The rate of heat generated is

Question 13 :
The smallest resistance that can be obtained by combining 10 resistors each of resistance $10 \Omega$is

Question 14 :
The smallest resistance that can be obtained by the combination of &#160;$n$ resistors, each of resistance &#160;$R$ is:

Question 15 :
The temperature of a conductor is increased. The product of resistivity and conductivity:<br/>

Question 16 :
A piece of copper and another of germanium are cooled from room temperature to 80K. The resistance of

Question 17 :
Calculate the energy consumed by $2\ kW$ heater used for $1\ hr$ every day in a period of $30\ \text{days}$.

Question 18 :
How much units of energy is consumed in operating ten 50 watt bulbs for 10 hours per day in a month (30 days)

Question 19 :
We have n resistors each of resistance R. The ratio of the combination for maximum and minimum values is

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