Physics Past Questions and Answers

The theory of electronic conduction in solids, which satisfactorily explains the properties of conductors, insulators and semi-conductor,is?

A String theory
B Particle theory
C Group theory
D Band theory

Question 32:

I. The number of neutrons released exceeds the number that caused the fission.
II. There is loss of mass.
III. Energy is produced.
IV. Smaller nuclei merge to form larger nuclei
which of the statement above are correct about nuclear fission?

A II,III and IV only
B I, II and IV only
C I,II and III only
D I, III and IV only

Question 33:

A certain manufacturer wishes to make an n-type semiconductor. Which materials would he select for doping?

A Boron and antimony
B Boron and antimony
C Aluminium and indium
D Arsenic and antimony

Question 34:

A p-n junction diode is used as?

A A rectifier in a d.c circuit
B An amplifier in d.c circuit
C An anplifier in an a.c circuit
D A rectifier in an a.c circuit

Question 35:

An object placed 10cm from a concave mirror of focal length 5cm would have its image

A At the centre of convature
B At the radius of curvature
C At infinity
D 10 cm from the focus