Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: R

There are no items in this cart.
Continue Shopping
Get instant 20% OFF on Online Material.
coupon code: MOB20 | View Course list

Get extra R 650 off


why we use tongstone in electrical bulbs?

6 years ago


Answers : (2)


Dear rakesh,

The spectrum emitted by a black body radiator does not match the sensitivity characteristics of the human eye. Tungsten filaments radiate mostly infrared radiation at temperatures where they remain solid.

No known material can be used as a filament at this ideal temperature, which is hotter than the sun's surface. An upper limit for incandescent lamp luminous efficacy is around 52 lumens per watt, the theoretical value emitted by tungsten at its melting point.

We are all IITians and here to help you in your IIT JEE preparation.

All the best.

 If you like this answer please approve it....

win exciting gifts by answering the questions on Discussion Forum


Sagar Singh

B.Tech IIT Delhi


6 years ago

Because of high resistace and high melting point.

6 years ago

Post Your Answer

Other Related Questions on Physical Chemistry

what is ment by enthaply........................................................?
@ shrada 1- enthalpy is a measure of total energy of a thermodynamic system , it includes the internal energy , which is energy required to create a system , 2- unit of enthalpy is joule...
Umakant biswal one month ago
It's a thermodynamic constant or a qiantity which is the sum of tital heat of the system. it is given as sum of total internal enrgy with product of pressure and volume.
Vikas TU one month ago
enthalpy is the some of internal energy and pressure volume work or it is the heat q at const...
anand 3 days ago
Please urgent. Thermochemistry question. I want to know the difference in energies and which one will be more stable and why?
Dear student The isomerised product will be more stable here due to conjugation which will lead to resonance.
Bhavya one month ago
thermodynamics,chemistry question is attached....................................
U=nc(at const. vol.)dt=5000J, but how come the answer is 6000J.........................................................
Naveen Shankar one month ago
The system is working at constant pressure. hence Change in internal energy is given as: U = F/2 nRt + (F/2+1)nRt here t is change in temp from final to initial. F is degree of freedom. n...
Vikas TU one month ago
for redox reaction Zn + NO 3 - = Zn 2+ + NH 4 + in basic medium, coefficient of Zn amd OH - in the balanced equation respectively are ?
Separate them into half reactions foirst and then balce it. Zn ------> Zn 2+ + 2e- AND NO3- ------> NH4+ + 3H2O NO3- + 10H+ +8e- ------> NH4+ + 3H2O In order to cancel the electrons add the ...
Vikas TU 2 months ago
no of geometrical and optical isomers of the compound [co(NH3)2Cl2(en)]+
This is M(AA)a 2 b 2 type compund.I have 3 G.I out of which two are trans which can’t show optical isomerism (O.I) While cis form show O.I hence occur in d & l pair Thus,3G.I & 2 O.I but...
Pranav Dabhade 2 days ago
Write differences between double salt and common salt.
Double salts are formed by mixture of two normal or simple salts obtained through crystallization. for example-dolomite. Common salt is the common name of NaCl and isan example of normal...
Mudit 2 months ago
View all Questions »

  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: R 15,000
  • View Details
Get extra R 3,750 off

Get extra R 650 off

More Questions On Physical Chemistry

Ask Experts

Have any Question? Ask Experts

Post Question

Answer ‘n’ Earn
Attractive Gift
To Win!!!
Click Here for details