In an experiment the angles are required to be measured using an instrument. 29 divisions of the main scale exactly coincide with the 30 divisions of the vernier scale. If the smallest division of the main scale is half -a-degree (0.5°), then the least count of the instrument is:

Question

In an experiment the angles are required to be measured using an instrument. 29 divisions of the main scale exactly coincide with the 30 divisions of the vernier scale. If the smallest division of the main scale is half -a-degree (0.5°), then the least count of the instrument is: (A) half minute (B) one degree (C) half degree (D) one minute

Tardigrade Admin · Accepted Answer

29 division of main scale coincides with 30 divisions of vernier scale Hence one division of vernier scale =(30-29/30) of main scale =(1/30) × 0.5°=(1/30) × 0.5 × 60 min =1 min.

Q. In an experiment the angles are required to be measured using an instrument. $29$ divisions of the main scale exactly coincide with the $30$ divisions of the vernier scale. If the smallest division of the main scale is half -a-degree $(0. 5^{\circ})$ , then the least count of the instrument is:

half minute

one degree

half degree

one minute

$29$ division of main scale coincides with $30$ divisions of vernier scale Hence one division of vernier scale
$= \frac{30 - 29}{30}$ of main scale
$= \frac{1}{30} \times 0. 5^{\circ} = \frac{1}{30} \times 0.5 \times 60 min = 1 min$ .

Q. In an experiment the angles are required to be measured using an instrument. 29 divisions of the main scale exactly coincide with the 30 divisions of the vernier scale. If the smallest division of the main scale is half -a-degree (0.5∘), then the least count of the instrument is: