Carbon, silicon and germanium have four valence electrons each. At room temperature which one of the following statements is most appropriate ?

  • Option 1)

    The number of free electrons for conduction is significant only in Si and Ge but small in C.

  • Option 2)

    The number of free conduction electrons is significant in C but small in Si and Ge.

  • Option 3)

    The number of free conduction electrons is negligibly small in all the three.

  • Option 4)

    The number of free electrons for conduction is significant in all the three.

 

Answers (1)

As we learnt in

Insulator -

When energy gap is more than 3 e.v.

- wherein

1) Electrical conductivity is negligible     

2)\Delta E_{g} > 3\: ev

3) Free electrons density is negligible

 

 

Semiconductor -

Energy gap between valence band and conduction band is less than 3 e.v.

- wherein

1) \Delta E_^{g} lies between conductor & insulator 

2) Both electron and holes are responsible for conductivity .

3)    At 0 K behave like an insulator (Si,Ge)

 

 Since carbon is non-metal while silicon and germanium are semiconductor hence at room temperature free electron for conduction is significant for Si and Ge but negligible in carbon. 

Correct option is 1.

 

 


Option 1)

The number of free electrons for conduction is significant only in Si and Ge but small in C.

This is the correct option.

Option 2)

The number of free conduction electrons is significant in C but small in Si and Ge.

This is an incorrect option.

Option 3)

The number of free conduction electrons is negligibly small in all the three.

This is an incorrect option.

Option 4)

The number of free electrons for conduction is significant in all the three.

This is an incorrect option.

Most Viewed Questions

Preparation Products

Knockout JEE Main April 2021 (One Month)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 14000/- ₹ 4999/-
Buy Now
Knockout JEE Main May 2021

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 22999/- ₹ 9999/-
Buy Now
Test Series JEE Main May 2021

Unlimited Chapter Wise Tests, Unlimited Subject Wise Tests, Unlimited Full Mock Tests, Get Personalized Performance Analysis Report,.

₹ 6999/- ₹ 2999/-
Buy Now
Knockout JEE Main May 2022

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 34999/- ₹ 24999/-
Buy Now
JEE Main Rank Booster 2021

Booster and Kadha Video Lectures, Unlimited Full Mock Test, Adaptive Time Table, 24x7 Doubt Chat Support,.

₹ 13999/- ₹ 6999/-
Buy Now
Boost your Preparation for JEE Main 2021 with Personlized Coaching
 
Exams
Articles
Questions