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

  • Complete Physics Course - Class 11
  • OFFERED PRICE: R 2,800
  • View Details
Get extra R 700 off


why do we have free electrons in metal and not in insulators...what makes them to be an insultaor/semiconductor/metal?

6 years ago


Answers : (1)


there is a gap called energy band gap denoted by Eg which is the gap between conduction band & valence band.since Eg for metals is approx. equal to 0.e- can easily jump from valence band(vb) to the conduction band(cb) & hence we have free e-.on the other hand Eg for semiconductors is < 3ev.hence e- can make a jump but at higher temp.and for insulators Eg is > 3ev making no free e- to jump.

for further info. refer NCERT,part 2,ch-14(pg-469)

6 years ago

Post Your Answer

Other Related Questions on Modern Physics

In pulley mass system of two masss such that m2 > m1.We make diection of acceleration as positive or we see the coordinate system signs ?? sign convention.
Take accln. according to the masses. The greater mass would have greater and positive accleration. and in pulley system i think that would be in vertical downward direction as heavier mass...
Vikas TU 2 months ago
give some examples to show the difference between linear and angular aceleration
linear accelration is used for linear motion or any trajectory motion. whereas, angular acceleration is strictly used for circular motion or a part of the circular curved motion. The...
Vikas TU 22 days ago
Explain the characteristics of photoelectric effect on the basis of Einstein’s photoelectric equation.
From Einstein’s photoelectric theory, light gets emiited from the sorce of light in the form of bundeles and he called it photons. he gave therfore an eqn. E =hv h is plancks constant and...
Vikas TU 3 months ago
What is fundamental frequency?and explain?????????????????????????
hi ,, fundamenatal frewuency is defined as the lowest frequency is produced by the oscillation is called fundamenntal..
T.kumar 9 months ago
Hello Gowri The fundamental frequency , often referred to as simply as the fundamental , is defined as the lowest frequency of a periodic waveform. In music, the fundamental is the musical...
Gaddam Chethan 9 months ago
the lowest frequency which is produced by the oscillation of the whole of an object,as distinct from the harmonics of higher frequency.the lowest frequency produced by source is called...
sudarshan 9 months ago
Date of JEE advanced exam 2016? any idea????????????????????
Its on 22 nd May
Harsh Patodia 8 months ago
Four particles each having a charge q, are placed on four vertices of a regular pentagon.The distance of each corner from the center is ‘a’ .Find the electric field at the centre of the...
If there were 5 charges at each corner then the net electric field at the centre would be 0 since it is a regular polygon .the electric field due to 4 charges will be equal and opposite to...
krishna priya 3 months ago
View all Questions »

  • Complete Physics Course - Class 12
  • OFFERED PRICE: R 2,600
  • View Details
Get extra R 650 off

  • Complete Physics Course - Class 11
  • OFFERED PRICE: R 2,800
  • View Details

Get extra R 700 off

More Questions On Modern Physics

Ask Experts

Have any Question? Ask Experts

Post Question

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