Question

A 1 m scale is used measure a 1 km long path. The possible parallax error in each
measurement is †1 mm . Actual length of the path can be-(A) 1000m to 1001m
(B) 999m to 1001m
(C) 999m to 1000m
(D) 1000m to 1002m​

Answer 1

Answer:

A

Explanation:

A length of 1km = 1000m

the error is +1mm per measure

The total no. of counts is 1000 so, the total error =1000*1mm=1000mm

1000mm=100cm=1m

Therefore , the distance will be 1000m+1m=1001m

Answer 2

Given,

A scale of the measurement = 1mm

Possible parallax error in each measurement = +1mm

To find,

The actual length of the path.

Solution,

In a length of 1km, there are 1000m.

The observed displacement of an item produced by a shift in the observer's point of view is known as parallax.

Since the parallax error is +1mm per measurement,

And the total number of counts = 1000

So, the total error = 1000 x 1mm=1000mm

And we also know that,

1000mm=100cm=1m

Therefore, the distance will be 1000m+1m=1001m.

Hence, the actual length of the path can be 1000m to 1001m (option a).