Bulbs

Q.

The Gas Usually Filled In the Electric Bulb Is a) Hydrogen B) Oxygen C) Nitrogen D) Carbon Dioxide

Q.

Why is eddy current bad?

Q. What material is used in making the filament of an electric bulb ?

Q.

Even currents of very low magnitude can lead to death. Is heat produce by the electric current responsible for the death ? Explain.

Q. A 25W and 100W bulb are joined in series and connected to the mains. Which bulb will glow brighter?

1. 25 W bulb
2. 100 W bulb
3. Both bulb will glow brighter
4. None will glow brighter

Q. Filament of a bulb is made up of tungsten.

1. False
2. True

Q. Which of the following things can be used as a filament of electric bulb?

1. Tungsten
2. Tin
3. Lead
4. Steel

Q.

Inside an electric bulb

1. There is vacuum

2. Air is filled inside

3. Inert gases are filled

4. Hydrogen gas is filled

Q.

Name the material used for:

Filament of an electric bulb

Q.

Name the gas found inside an electric bulb?

Q. A bulb draws current 1.5 A at 6.0 V. Find the resistance of filament of bulb while glowing.

Q. When a bulb consumes more power, it appears brighter.

1. True
2. False

Q. Which material shows the property of superconductivity?

1. 600
2. 560
3. 460
4. 500

Q. The filament of a bulb is usually a:

1. thin wire with many coils
2. thick wire with many coils
3. thin straight wire
4. thick straight wire

Q.

Name the following:
This gas is used in electric bulbs.

Q. The filament of a bulb is usually a

1. Thin wire with many coils
2. Thin straight wire
3. Thick wire with many coils
4. Thick strength wire

Q. The filament of bulb offers ______ resistance to electric current.

1. no
2. low
3. high
4. very low

Q.

How much current will an electric bulb draw from a $220V$source, if the resistance of the bulb filament is $1200\Omega$?

Q. What are the advantages of using tungsten as a filament?

Q. Mark the correct reason why tungsten is used for making filament of electric lamp.

1. Tungsten oxidizes easily
2. It has low boiling point
3. It has high melting point
4. None

Q. The material which is used as a filament for bulb has high ____________ .

1. Boiling point
2. Melting point
3. freezing point
4. pressure

Q.

What will happen when we do wiring of a house with 2.5mm² instead of 1mm² cross section area of wire. Is extra current used or current is wasted?

Q. Explain why , filament type electric bulbs are not power efficient.

Q. When a bulb consumes more power, it appears brighter.

1. False
2. True

Q. State two characteristics of a good thermion emitter.

Q.

A student uses two wires of copper and nichrome of equal length . He first joins the two wires in series and passes electric current through the combination which increases gradually . after that the two wires are connected in parallel and repeats the process of passing the current . Which wire will glow first in each case and why ?

Q. Which material is used as filament of bulb?

Q. The electric bulbs have tungsten filaments of the same length. If one of them gives $60$ watt and other $100$ watts, then

1. $100$ watt bulb has thicker filament
2. $60$ watt bulb has thicker filament
3. Both filaments are of same thickness
4. It is possible to get different wattage unless the lengths are different

Q. Assertion :Through the same current flows through the linewires and the filament of the bulb but heatproduced in the filament is much higher then thatin line wires. Reason: The filament of bulbs is made of a material of high
resistance and high melting point.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect