Which of the following is the correct definition of 'half-life'?
the average life-time of a radioactive material
the time it takes a radioactive material to decay to half of its original quantity
half the period a radioactive material decays completely
half of the decay constant
the decay constant times life-time
Correct answer is B
No explanation has been provided for this answer.
5 volts
3.5 volts
2.5 volts
1 volts
10 volts
Correct answer is B
E.m.f. = I(R + r) = 0.5(2+5) = 3.5 volts
heating the bar to a high temperature
breaking the bar
connecting opposite poles with a small piece of iron
placing the bar inside a strong magnetic field
none of the above
Correct answer is A
No explanation has been provided for this answer.
What are the units of thermal conductivity?
kg.m.sec2
Joule sec-1m-1k-1
kg.m
Newton sec-1m2
m3
Correct answer is B
No explanation has been provided for this answer.
the cross-sectional area of the tube
the atmospheric pressure
the density of mercury
the temperature of mercury
the acceleration due to gravity
Correct answer is A
No explanation has been provided for this answer.