Physics Questions and Answers
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
A radioisotope has a decay constant of 10−7s−1. The average life of the radioisotope is
1.00 x 107s
6.93 x 106s
1.00 x 10-7s
6.93 x 107s
Correct answer is B
Average life / Half life (T12) = ln2/λ = 0.693/10−7
= 0.693 x 107
= 6.93 x 106
The major difference between a pure semiconductor and a pure metal is that
metals are harder than semiconductor
while resistance of metals decrease with temperature , the reverse is the case for semiconductor
the resistance of metals increases with temperature, while for semiconductors, it is the reverse
metals have forbidden gaps while semiconductors have not
Correct answer is C
Experiment shows that increase in temperature increases the resistance of a pure metal but decreases the resistance of pure semiconductor
In a semi conductor junction diode, as the depletion or barrier layer is forward-biased, the layer
widens
narrows
remains constant
widens then narrows
Correct answer is C
No explanation has been provided for this answer.