JAMB Physics Past Questions & Answers - Page 401

2,001.

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

Correct answer is A

No explanation has been provided for this answer.

2,002.

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

Correct answer is D

No explanation has been provided for this answer.

2,003.

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

A.

boron and antimony

B.

boron and sodium

C.

aluminium and indium

D.

arsenic and antimony

Correct answer is D

An n- type semi conductor is usually formed by dopping the semi conductor(a four valent element)with a five valent
element.(arsenic and antimony)

2,005.

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

Correct answer is D

No explanation has been provided for this answer.