Physics Past Questions and Answers

An electron of charge 1.6 x 10^-19C and mass 9.1 x 10^-31kg is accelerated between two metal plates with a velocity of 4 x 10⁷ms^-1, the potential difference between the plates is

A 4.55 x 10³V
B 4.55 x 10²V
C 9.10 x 10¹V
D 4.55 x 10¹V

Question 1017:

A cell of internal resistance 0.01â„¦ can be measured accurately using the

A Ohm meter
B Metre bridge
C Potentiometer
D Electroscope

Question 1018:

What optical instrument can best be constructed with converging lenses of focal lengths 50cm and 5cm?

A Compound microscope
B Galileo's telescope
C Terrestrial telescope
D Astronomical telescope

Question 1019:

in a pure semiconductor, the number of electrons in the conduction band is

A Less than the number of holes in the valence band
B Equal to the number of holes in the valence band
C Greater than the number of holes in the valence band
D Twice the number of holes in the valence band

Question 1020:

In a thermonuclear reaction, the total initial mass is 5.02 x \(10^{-{2}{7}}\)kg and the total final mass is 5.01 x \(10^{-{2}{7}}\)kg. The energy released in the process is
[c = 3.0 x \(10^8\) ms-1]

A 9.0 x 10^-13J
B 9.0 x 10^-12J
C 9.0 x 10^-11J
D 9.0 x 10^-10J