Measurement of Length, Mass and Time

What do you mean by parallax angle?

How many wavelength of ${\mathrm{Kr}}^{86}$ are there in one meter?

$1 \mathrm{AU}$ is equal to

$1 \mathrm{A}$ is equal to

Which is the most accurate clock ?

What is the size of our galaxy?

Suppose the universe were shrunk to the size of the earth how large would the earth be on such a scale?

What is parallax?

ls there any specific reason for using $\mathrm{Cesium}-133$ atom for defining one second?

Which is greater, pound or kilogram ?

What is $\text{'}\mathrm{u}\text{'}$?

Do we have an atomic standard of mass? Why?

Define par sec and light year. How are they related?

What is the difference between $\stackrel{\circ }{\mathrm{A}}$ and $\mathrm{A}.\mathrm{U}.$?

What is one fermi?

What is Planck length?

How is the distance from the moon to the earth determined?

How is the method of parallax used to find the distance of a planet?

Explain parallax.

What is the range of length which we come across in Physics ?