Question 1 :
You have the following appliances each of $500\ W$ running on  $220\ V$ a.c.: (1) Electric iron.(2) Electric lamp. (3) Electric room heater. The electric resistance is:
Question 2 :
Two resistors are connected a) in series b) in parallel.<br>The equivalent resistance in two cases are $9\ ohm$ and $2\ ohm$ respectively. Then the resistance of the component resistors are.
Question 3 :
An electric lamp is marked $60\ W,\ 220\ V$. The cost of kilo watt hour of electricity is $Rs.\ 1.25$. The cost of using thing lamp on $220\ V$ for $8\ hrs$ is:
Question 4 :
In a given themocouple, the temperature of cold junction is $20^oC$ while the temperature is $270^oC$. The temperature of inverson is
Question 5 :
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 heated to 100$^0$C. The potential drop in the two resistance is measured. Which of the following statements is correct? 
Question 6 :
What is the total resistance when four resistors of $20, 40, 60$, and $80$ respectively are connected in parallel (in ohm)?
Question 7 :
Which of the following will produce maximum wastage of electricity ?
Question 8 :
A piece of copper and another of germanium are cooled from room temperature to 80K. The resistance of
Question 9 :
Shivam went for buying a CFL from D-mart, what safety mark he should look for?
Question 10 :
Mark the correctreason/s why nichrome is used for making heating element of electricalappliances.
Question 12 :
Why is electric power transmitted over long distances at high voltage?<br>
Question 13 :
From below which are the applications of heating effect of electric current?<br>
Question 15 :
An electric heater of resistance $6\ \Omega $ is run for $10\ min$ on a line of $120\ V$. The energy liberated in this period of time is:<br/>
Question 16 :
The current in a wire is doubled keeping temperature constant. Which of the following statements is/are wrong?
Question 17 :
The overheating of electrical wiring in any circuit due to the flow of large current through it is called _________ of the electric circuit.<br/>
Question 18 :
Which is the equivalent resistance when resistors $3 \Omega$ and $6 \Omega$ are in parallel?<br>
Question 19 :
The emf of the battery in a thermocouple is doubled. The rate of heat generation at one of the junctions will 
Question 20 :
As the temperature of a conductor increases, its resistivity and conductivity change. The ratio of resistivity to conductivity<br>
Question 21 :
The resistance of a hot tungsten filament is about $10$ times the cold resistance. What will be the resistance of $100\ W,\ $ <br> $200\ V$ lamp when not in use?
Question 22 :
A thermocouple is made from copper and iron. at the hot junction, the current
Question 23 :
The thermo-emf of a copper-constant couple is $40\muV$ per degree. The smallest temperature difference that can be detected with this couple and galvanometer of $100\Omega$ resistance capableof measuring the minimum current of $1\mu A$ is
Question 26 :
A typical thermistor can easily measure a change in temperature of the order of
Question 27 :
Which of the following equipment does not work on principle of Joule's law?
Question 28 :
Mark the correctreason why tungsten is used for making filament of electric lamp.
Question 29 :
A current $i$ passes through a wire of length $L$, radius $R$ and resistively $\rho$. The rate of heat generated is
Question 31 :
The smallest resistance that can be obtained by combining 10 resistors each of resistance $10 \Omega$is
Question 32 :
In our houses all electrical devices operate on 220 V. It implies that
Question 33 :
When the electric resistance are connected in parallel, which one of the following quantities is not affected ?
Question 34 :
The temperature of a conductor is increased. The product of resistivity and conductivity:<br/>
Question 35 :
An electric fuse used in households works on which principle of:<br/>
Question 36 :
Three resistors each having same resistance are connected in parallel. Their equivalent resistance is$\displaystyle 5\Omega$. If they are connected in series, their equivalent resistance is.
Question 39 :
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 40 :
When a metallic conductor is heated then the atoms in the metal vibrate with ?<br/>
