Question 1 :
Why are bulbs filled with chemically inactive Nitrogen or Argon gas?<br>
Question 2 :
Identify the changes in a circuit on adding a light bulb in parallel to the actual resistance of the circuit. It will:<br/>
Question 3 :
For a heater rated at4.4 kW; 220 V . Calculate the energy consumed by the heater in 4 hours?
Question 4 :
The smallest resistance that can be obtained by combining 10 resistors each of resistance $10 \Omega$is
Question 5 :
Two wires of Aluminium have same weight and have lengths of 10m and 20m. Their resistances are in the ratio.<br/>
Question 6 :
A piece of copper and another of germanium are cooled from room temperature to 80K. The resistance of
Question 7 :
When a metallic conductor is heated then the atoms in the metal vibrate with ?<br/>
Question 8 :
From below which are the applications of heating effect of electric current?<br>
Question 9 :
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 10 :
A typical thermistor can easily measure a change in temperature of the order of
Question 11 :
The heating element in an electric iron is made up of :
Question 12 :
When the electric resistance are connected in parallel, which one of the following quantities is not affected ?
Question 13 :
As the temperature of a conductor increases, its resistivity and conductivity change. The ratio of resistivity to conductivity<br>
Question 15 :
Shivam went for buying a CFL from D-mart, what safety mark he should look for?
Question 16 :
Which is the equivalent resistance when resistors $3 \Omega$ and $6 \Omega$ are in parallel?<br>
Question 18 :
An electric bulb of $60\ W$ is used for $6\ hrs/day$. Calculate the units of energy consumed in one day by the bulb.
Question 19 :
Which of the following will produce maximum wastage of electricity ?
Question 20 :
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 21 :
A constant voltage is applied between the two ends of uniform metallic wire, some heat is developed in it. If both the length and the radius of the wire halved, the heat developed in the same duration will become
Question 22 :
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 23 :
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 26 :
An electric fuse used in households works on which principle of:<br/>
Question 27 :
How much units of energy is consumed in operating ten 50 watt bulbs for 10 hours per day in a month (30 days)
Question 28 :
Two resistors of resistance $\displaystyle { R }_{ 1 }$ and$\displaystyle { R }_{ 2 }$ having$\displaystyle { R }_{ 1 }>{ R }_{ 2 }$ are connected in parallel. For equivalent resistance R, the correct statement is
Question 29 :
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 30 :
The neutral temperature of a thermocouple is 275$^oC$ and the temperature of inversion is 600$^oC$. The temperature of the cold junction is
Question 31 :
A 24V potential difference is applied across a parallel combination of four 6 ohm resistor. The current in each resistor is:<br/>
Question 32 :
The cells are joined in parallel to get the maximum current when
Question 33 :
Why is electric power transmitted over long distances at high voltage?<br>
Question 34 :
Calculate the energy consumed by $2\ kW$ heater used for $1\ hr$ every day in a period of $30\ \text{days}$.
Question 36 :
If five equal pieces of $25\Omega$ are connected in parallel, then their equivalent resistance will be............
Question 37 :
The smallest resistance that can be obtained by the combination of  $n$ resistors, each of resistance  $R$ is:
Question 38 :
Mark the correctreason/s why nichrome is used for making heating element of electricalappliances.
Question 39 :
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 40 :
A thermocouple is made from copper and iron. at the hot junction, the current
Question 41 :
The emf of the battery in a thermocouple is doubled. The rate of heat generation at one of the junctions will 
Question 42 :
In a given themocouple, the temperature of cold junction is $20^oC$ while the temperature is $270^oC$. The temperature of inverson is
Question 43 :
A current $i$ passes through a wire of length $L$, radius $R$ and resistively $\rho$. The rate of heat generated is
Question 44 :
Constantan wire is used for making standard resistance, because it has
Question 45 :
Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?<br>
Question 47 :
A resistor connected to a battery is heated due to current through it. Which of the following quantity does not vary?<br>
Question 48 :
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 49 :
Which of the following equipment does not work on principle of Joule's law?
Question 50 :
We have n resistors each of resistance R. The ratio of the combination for maximum and minimum values is
