JEE Main · 2021 · 17 Mar 2021 · Shift 1 · Units & Measurement

WhatsApp Email
The vernier-scale used for measurement has a positive zero error of 0.2 mm. If while taking a measurement it was noted that '0' on the vernier-scale lies between 8.5 cm and 8.6 cm, vernier coincidence is 6, then the correct value of measurement is (least count cm):
  1. (A)8.36 cm
  2. (B)8.58 cm
  3. (C)8.54 cm✓ Correct
  4. (D)8.56 cm

Answer: (C)

Solution

The observed reading is the main scale reading plus the vernier coincidence multiplied by the least count:

A positive zero error is subtracted from the observed reading, and , so

The correct value of the measurement is cm.

JEE Main · 2021 · 17 Mar 2021 · Shift 1 · Single correct option

More JEE Main questions on Units & Measurement

  1. If ε, E and t represent the free space permittivity, electric field and time respectively, then the unit of will be :
    JEE Main 2026View solution →
  2. Keeping the significant figures in view, the sum of the physical quantities and 0.123 m is :
    JEE Main 2026View solution →
  3. A spherical body of radius and density falls freely through a viscous liquid having density and viscosity and attains a terminal velocity . Estimated maximum error in the quantity is : (Ignore errors associated with …
    JEE Main 2026View solution →
  4. Four persons measure the length of a rod as , , and . The relative error in the measurement of average length of the rod is:
    JEE Main 2026View solution →
  5. In a screw gauge, the zero of the circular scale lies 3 divisions above the horizontal pitch line when their metallic studs are brought in contact. Using this instrument thickness of a sheet is measured. If pitch scale reading is 1 mm and the circular scale reading is 51 then the …
    JEE Main 2026View solution →
  6. A ball of radius r and density dropped through a viscous liquid of density and viscosity attains its terminal velocity at time t, given by , where A is a constant and a, b, c and d are integers. The value of …
    JEE Main 2026View solution →