A substance has half of 3 min. After 6 min, the count rat...
A substance has half of 3 min. After 6 min, the count rate was observed to be 400. What was its count rate at zero time?
1600
1200
200
2400
Correct answer is A
Let the count rate at zero time be N
N \(\frac{3 min}{\to}\) \(\frac{N}{2}\) \(\frac{3 min}{\to}\) \(\frac{N}{4}\)
\(\frac{N}{4}\)
= 400
N = \(\frac{400}{N/4}\) x N
= 1600
A cell of internal resistance 1Ω supplies current to an external resistor of 3Ω. The efficiency ...
Which of the following properties is NOT exhibited by sound waves? ...
An instrument used to measure relative humidity is the? ...