It talks about the uncertainty. 2% means that during first time interval the 2% of the nuclei decay and 98% remain. That's why we multiply the initial number of nuclei by 0.98 to get the nuclei we have. And for the maximum uncertainty of 10%,the 10% of original nuclei should have decayed and so at that time we'll have 90% of the initial nuclei. That's how I have done it. Mark scheme changes it directly to 92% for further calculation.
It talks about the uncertainty. 2% means that during first time interval the 2% of the nuclei decay and 98% remain. That's why we multiply the initial number of nuclei by 0.98 to get the nuclei we have. And for the maximum uncertainty of 10%,the 10% of original nuclei should have decayed and so at that time we'll have 90% of the initial nuclei. That's how I have done it. Mark scheme changes it directly to 92% for further calculation.
But that's a 2% uncertainty how does it imply a decay of nuclei ?
But that's a 2% uncertainty how does it imply a decay of nuclei ?
It means that there will be an error of 2% while measuring the count rate. So to make allowance for the error, I have assumed that 2% of it decays during the first time interval. Anyway, I don't think that my way is perfect(although it does give the correct answer), so I think you should make a thread about it in physics help forum.
It means that there will be an error of 2% while measuring the count rate. So to make allowance for the error, I have assumed that 2% of it decays during the first time interval. Anyway, I don't think that my way is perfect(although it does give the correct answer), so I think you should make a thread about it in physics help forum.
Any idea why the amplitude of the information signal has to be less than half the amplitude of the carrier wave ?
Any idea why the amplitude of the information signal has to be less than half the amplitude of the carrier wave ?
As the course book says, "the variation in amplitude at top would be confused with the variation in amplitude at bottom of the wave". Too bad that it doesn't say much more about it.