The main scale of a vernier callipers has n

The main scale of a vernier calliper has \(n\) divisions/cm. \(n\) divisions of the vernier scale coincide with \((n-1)\) divisions of the main scale. The least count of the vernier calliper is: 1.\(\frac\) cm NEET Practice Questions, MCQs, Past Year Questions (PYQs), NCERT Questions, Question Bank, Class 11 and Class 12 Questions, and PDF solved with answers A student performs an experiment to determine Young's modulus of a wire, exactly 1 m long by Searle's method. In a particular reading, the student measures extensions in the length of the wire to be 4.00 mm with an uncertainty of ± 0.01 mm at a load of exactly 1 kg. The student also measures the radius of wire to be 1.00 mm with an uncertainty of ± 0.005 mm. The Young's modulus obtained from the reading is (Take g = 10 m / s 2) :

A quick guide on how to read a centimetres (cm) and it is precise up to 2 decimal places (E.g. 1.23 cm). Note: The measurement-reading technique described in this post will be similar for vernier calipers which output measurement readings in inches. Measurement Reading Technique For Vernier Caliper In order to read the measurement readings from vernier caliper properly, you need to remember two things before we start. For example, if a vernier caliper output a measurement reading of 2.13 cm, this means that: • The main scale contributes the main number(s) and one decimal place to the reading (E.g. 2.1 cm, whereby 2 is the main number and 0.1 is the one decimal place number) • The vernier scale contributes the second decimal place to the reading (E.g. 0.03 cm) Let’s examine the image of the vernier caliper readings above. We will just use a two steps method to get the measurement reading from this: • To obtain the main scale reading: Look at the image above, 2.1 cm is to the immediate left of the zero on the vernier scale. Hence, the main scale reading is 2.1 cm • To obtain the vernier scale reading: Look at the image above and look closely for an alignment of the scale lines of the main scale and vernier scale. In the image above, the aligned line correspond to 3. Hence, the vernier scale reading is 0.03 cm. In order to obtain the final measurement reading, we will add the main scale reading and vernier scale reading together. This will give 2.1 cm + 0.03 cm = 2.13 cm. In ...

Solution It is given that nVSD= (n-1)MSD 1 V S D = ( n − 1 ) n M S D Least count is difference between main scale division and vernier scale division. L C = 1 M S D − 1 V S D = 1 M S D − ( n − 1 ) n M S D = 1 2 M S D There are n divisions per cm, hence each main scale division is equivalent to 1 n c m. L C = 1 n × 1 n c m = 1 n 2 c m.