Engg chemistry for EEE stream

In conductors the gap between valence and conduction band will be............

• large

• moderate

• no gap

• no bands at all

which of the following technique is not a method of preparation of semiconductors

• Czochralski process

• pulling technique

• float zone process

• kjeldahal process

In Czocholski process ambient control unit is used to

• remove oxygen from the bath

• to maintain temperature

• to add oxygen to the bath

• no ambient control unit at all

melting point of silicon is

• 1417 degree C

• 1991 degree C

• 181 degree C

• 97 degree C

dopant to be added to synthesise n-type semiconductor in Fload Zone process is

• PH3

• B2H6

• NaMO2

• Argon Gas

identify the process

• Float Zone

• Czochrolski

• pulling

• Moving boundary

Reason for conducting mechanism in polyacetylene is

• Exitons

• Free radicals

• Carbo cations

• Carbenes

catalyst used for the synthesis of polyacetylene is

• tetrabutoxy titanium

• silver chloride

• triethyl aluminium

• both 1 and 3

buffer solution used in electroless coating

• acetic acid

• ammonium acetate

• sodium hydroxide

• lithium chloride

reducing agent used for the electroless coating of copper

• urea

• formaldehyde

• acetaldehyde

• acetone