# All Questions

46 questions
73 views

### Problem in measuring uncertainty

While performing an experiment involving a bar pendulum, we had to measure the time period of one oscillation by measuring the time taken for 30 oscillations. There is some confusion regarding ...
136 views

### Why does taking more readings reduce random error? [closed]

So I was tossing a coin And I did two experiments Experiment 1: Tossing same Coin with no fan with different torque each time and did'nt much care about orientation of the coin, 8 times I got 5 ...
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### Propagation of uncertainty in integral formula

I have a moving object with mass $M$ whose 1D trajectory $x$ can be tracked and known over time with a certain sampling rate (EDIT: to make it clear, I don't have the analytical form of $x$, that's a ...
32 views

### How to get second-order equation from 2 first-order equations with the same dependent variable?

I have a current sensor thats returns an output in voltage (Ts) dependent on the current that passes throught the inputs (I) and the voltage feed input (Ta). I built a table and measured the Ts, while ...
42 views

### Assigning distributions to the result of measurements

In my data analysis course we were taught that whenever we perform a measurement, the measured value is to be interpreted as the mean of the distribution for the true value. And the error in ...
43 views

### Covariance when two parameters have relative scaling error

I was reading error propagation from "Introduction to Statistics and Data Analysis for Physicists" by G. Bohm and G. Zech, and I stumbled upon this example, Given are the sides a, b with a reading ...
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### Replacing '< x' by a defined value [closed]

I do have a dataset containing nearly a decade of particulate matter measurements. At the lower precision limit of the measuring instrument, there are values given like ...
150 views

So in class we are doing an experiment on the period of a pendulum where you measure the period of oscillation with a stopwatch. Now the way the lab manual shows how to do the error analysis is by ...
58 views

### When analyzing data from an experiment, is each $x_i$ a random variable?

When we perform one experiment we have to measure several quantities and take some number of measurements for each of them. Those quantities can be things like positions, instants of time, and so ...
271 views

### Why do we divide the standard deviation by $\sqrt{n}$? [duplicate]

I've been studying experimental physics on the book "The art of experimental physics" and on the chapter about error analysis there's something that has been bothering me. The author says: Now that ...
204 views

### Combining two data points with different uncertainties

I have two separate algorithms (call them "A1" and "A2") which reconstruct the $(x, y)$-position of an event in a particle detector. I can test both of these algorithms on simulated events from a very ...
635 views

### Calculating statistical significance of peak over background in counting experiment

I histogrammed the invariant masses of particular events in a counting experiment. There is a specific peak which towers over the expected exponential background. How can I give the statistical ...
583 views

### How to find the error of all the counts within the Full Width Half Maximum (FWHM)?

We've been doing Gamma ray spectroscopy and have peaks from various sources. We'd use Poisson statistics, but obviously the detector doesn't have a resolution of zero, thus we are summing the counts ...
175 views

### Combining errors. Gamma spectrometry, Poisson distribution

I have run an experiment 3 times and measured the results by gamma spectrometry. For example I get values like this (1 $\sigma$): $100 (10)$ $90 (8)$ $110 (12)$ The above 1 sigma error is based ...
297 views

### Scale Factor on Error

I was gathering some data from the particle data group website and for many results it gives a value, an uncertainty and then a scale factor for the uncertainty. For instance, at here, where it gives ...
341 views

### Uncertainty of approximately sinusoidal voltage measurement

Say one is interested in measuring the mean value an approximately sinusoidal voltage with an instrument that has an accuracy of 0.01 V, according to its spec sheet. 10 periods of the oscillation have ...