Semiconductor and Thyristor Quiz

A semiconductor is formed by ......... bonds.

• Covalent

• Electrovalent

• Co-ordinate

• None of the above

A semiconductor has ............ temperature coefficient of resistance.

• Positive

• Zero

• Negative

• None of the above

The most commonly used semiconductor is ...........

• Germanium

• Silicon

• Carbon

• Sulphur

A semiconductor has generally .................. valence electrons.

• 2

• 3

• 6

• 4

The resistivity of a pure silicon is about ...............

• 100 O cm

• 6000 O cm

• 3 x 105 O m

• 6 x 10-8 O cm

In a semiconductor, current conduction is due to ........

• Only holes

• Only free electrons

• Holes and free electrons

• None of the above

The static V-I curve for the SCR is plotted for a) Ia (anode current) vs Ig (gate current), Va (anode – cathode voltage) as a parameter b) Ia vs Va with Ig as a parameter c) Va vs Ig with Ia as a parameter d) Ig vs Vg with Ia as a parameter

• a

• b

• c

• d

The two transistor model of the SCR can obtained by a) bisecting the SCR vertically b) bisecting the SCR horizontally c) bisecting the SCRs top two & bottom two layers d) bisecting the SCRs middle two layers

• a

• b

• c

• d

The di/dt rating of an SCR is specified for its (a) Decaying anode current (b) Decaying gate current (c) Rising gate current (d) Rising anode current

• a

• b

• c

• d

A forward voltage can be applied to an SCR after its (a) Anode current reduces to zero (b) Gate recovery time (c) Reverse recovery time (d) Anode voltage reduces to zero

• a

• b

• c

• d