Fill ups
If there is a large energy gap between the filled valence band and empty conduction band, the subtance acts as …………….. .

The question given below consist of an assertion (A) and a reason ( R). Use the following key to choose the appropriate answer to these questions from the codes (a), (b), ( c) and (d) given below: (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true but R is NOT the correct explanation of A. (c) A is true but R is false. (d) A is false and R is also false. Assertion: The energy gap between the valence band and conduction band is greater in silicon than germanium. Reason: Thermal energy produces fewer minority carries in silicon than in germanium.

The lowest unfilled energy band formed just above the valence band is called conduction band. (True/false)

What do you mean by valence band, conduction band and forbidden gap?

Energy of the photon of sodium light of wavelength 5,890 overset @A equals the energy gap between valence and conduction band of a semiconductor. Find the minimum energy E required to create a hole-electron pair.

Explain the formation of energy bands in solids and hence define conduction band and valence band.

Distinguish between energy levels and energy bands.

Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy band gap respectively equal to (Eg)_C , (Eg)_Si and (Eg)_ Ge . Which of the following statements is true?