Physics - Error Question with Solution | TestHub

To find the least count (LC) of the spectrometer, we use the formula:

LC = 1 MSD - 1 VSD

Given:

30 VSD = 29 MSD

1 VSD = (29/30) MSD

Substituting this into the LC formula:

LC = 1 MSD - (29/30) MSD

LC = (1/30) MSD

The main scale is divided into 720 divisions, which corresponds to 360 degrees.

Therefore, 1 MSD = 360 degrees / 720 divisions = 0.5 degrees.

Now, calculate the least count:

LC = (1/30) * 0.5 degrees

LC = 0.5 / 30 degrees

LC = 1/60 degrees

To convert degrees to arcminutes:

1 degree = 60 arcminutes

LC = (1/60) * 60 arcminutes

LC = 1 arcminute

The least count of the instrument is 1 arcminute.

The final answer is $\boxed{1arcminute}$.