English

Why is the tungsten used almost exclusively for filament of electric lamps?

Advertisements
Advertisements

Question

Why is the tungsten used almost exclusively for filament of electric lamps?

One Line Answer
Advertisements

Solution

The melting point of tungsten is an alloy that has a very high melting point (3380°C) and very high resistivity, so it does not burn easily at a high temperature.

shaalaa.com
  Is there an error in this question or solution?
Chapter 11: Electricity - EXERCISE [Page 194]

APPEARS IN

NCERT Science [English] Class 10
Chapter 11 Electricity
EXERCISE | Q 18. (a) | Page 194

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Why does the cord of an electric heater not glow while the heating element does?


Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.


An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.


Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?


How does the resistance of a wire vary with its area of cross-section?


An electric iron of resistance 20 ohms draws a current of 5 amperes. Calculate the heat produced in 30 seconds.


Explain why, the current that makes the heater element very hot, only slightly warms the connecting wires leading to the heater.


The current passing through a room heater has been halved. What will happen to the heat produced by it?


What is meant by the heating effect of current?


The current passing through an electric kettle has been doubled. The heat produced will become:

(a) half
(b) double
(c) four time
(d) one-fourth 


Give a scientific reason.

Tungsten metal is used to make a solenoid type coil in an electric bulb.


Name the factors on which the heat produced in a wire depends when current is passed in it, and state how does it depend on the factors stated by you.


What is the heating effect of electric current?


Write two devices based on the heating effect of electric current.


Write scientific reason.

A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.


What does overloading cause?


The heating element of an electric iron is made up of:


(a) Observe the diagram given below and state whether the bulb will glow or not when we switch on K.

(b) Is it safe to handle the bulb when the switch is OFF?

(c) Give a reason for your answer in (b).


Anannya responded to the question: Why do electrical appliances with metallic bodies are connected to the mains through a three-pin plug, whereas an electric bulb can be connected with a two-pin plug?

She wrote: Three-pin connections reduce heating of connecting wires.

  1. Is her answer correct or incorrect? Justify.
  2. What is the function of a fuse in a domestic circuit?

When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×