1. . Shape of a crystal is simple cubic when one atom lies at its:
(A) Eight corners
(B) Four corners
(C) Six corners
(D) Five corners
2. . Band theory of solids has explained the behaviour of:
(A) All of these
(B) Conductors
(C) Semiconductors
(D) Insulators
3. . Which of the following has the greatest energy gap:
(A) Conductor
(B) Insulator
(C) Semiconductor
(D) All of these
4. . The substances having intermediate values of resistivity are called:
(A) Semiconductor
(B) Insulator
(C) Conductor
(D) All of these
5. . An N-type semiconductor is obtained by adding impurity:
(A) Aluminium
(B) Antimony
(C) Boron
(D) Indium
6. . A P-type semiconductor is obtained by adding impurity in the form of:
(A) Indium
(B) Cobalt
(C) Phosphorus
(D) Antimony
7. . A forward biased diode has resistance:
(A) Zero
(B) Infinite
(C) High
(D) Low
8. . Semiconductor diode conducts only when it is:
(A) Reverse biased
(B) Forward biased
(C) Not biased
(D) All of these
9. . The reverse current through a semiconductor diode is due to:
(A) Minority carriers
(B) Majority carriers
(C) Holes
(D) Electrons
10. . Photo voltaic cell is a device which converts:
(A) Light into sound
(B) Light into chemical energy
(C) Chemical energy into light
(D) Light into electrical energy