Atomos Test Generator Free PYQs ExamsMy practice Log in / Sign up free

Units and Measurements

JEE Main 2026 (Online) 8th April Evening ShiftMCQMedium📈 Topic in 22% papers+4−1
Ques. 1JEE Main 2026, 8 April (Evening Shift)

Consider the equation H= xp qErts Where H = magnetic field intensity; E = electric field, = permittivity, x = distance, t = time The values of p, q, r and s respectively are :

  1. 1, 1, 1, 1
  2. -1, 1, 2, 1
  3. 1, -1, -2, 1
  4. -1, -2, -2, 1

Answer

(1) 1, 1, 1, 1

Solution

[H]=[ AL-1] (unit A/m), [ ]=[ M-1L-3T4A2], [E]=[ MLT-3A-1]

[ AL-1]=[L]p[ M-1L-3T4A2]q[ MLT-3A-1]r[T]-s

Comparing powers:

M: -q+r=0

A: 2q-r=1 q=r=1

T: 4q-3r-s=0 s=1

L: p-3q+r=-1 p=1

Check: E = surface charge density ( C m-2), so x Et has unit m C m-2s=A m-1

p, q, r, s=1, 1, 1, 1

Answer: (1)

Keep practising — Units and Measurements

Ques. 2JEE Main 2026, 6 April (Morning Shift)

The density of a uniform cylinder is determined by measuring its mass m, length l and diameter d. The measured values of m, l and d are 97.42 0.02 g, 8.35 0.05 mm and 20.20 0.02 mm, respectively. Calculated percentage fractional error in is .

  1. 0.63%
  2. 0.82%
  3. 0.72%
  4. 0.25%
Ques. 3JEE Main 2026, 6 April (Morning Shift)

The potential energy of a particle changes with distance x from a fixed origin as V= A xx+B, where A and B are constants with appropriate dimensions. The dimensions of AB are .

  1. [ M1L5/2T-2]
  2. [ M3/2L5/2T-2]
  3. [ M1L2T-2]
  4. [ M1L7/2T-2]
Ques. 4JEE Main 2026, 6 April (Evening Shift)

The percentage error in the calculated volume of a sphere, if there is 2% error in its diameter measurement, is .

  1. 1
  2. 2
  3. 6
  4. 8
Ques. 5JEE Main 2026, 6 April (Evening Shift)

Match List-I with List-II. Choose the correct answer from the options given below :

  1. A-I, B-II, C-III, D-IV
  2. A-IV, B-III, C-II, D-I
  3. A-III, B-IV, C-II, D-I
  4. A-II, B-I, C-IV, D-III
Ques. 6JEE Main 2026, 5 April (Morning Shift)

In a Vernier calipers, when both jaws touch each other, zero of the Vernier scale is shifted to the right of zero of the main scale and 7th Vernier division coincides with a main scale reading. If the value of 1 main scale division is 1 mm and there are 10 Vernier scale divisions, then the Vernier caliper has

  1. 0.07 cm negative zero error
  2. 0.7 cm negative zero error
  3. 0.07 cm positive zero error
  4. 0.7 cm positive zero error
Ques. 7JEE Main 2026, 5 April (Morning Shift)

L, C and R represents physical quantities inductance, capacitance and resistance respectively. The dimensional formula M L2 T-4 A-2 corresponds to .

  1. R LC
  2. RLC
  3. C LR
  4. 1R LC
Ques. 8JEE Main 2026, 5 April (Evening Shift)

Match List-I with List-II. where h (Planck's constant), G (gravitational constant) and c (speed of light in vacuum) as fundamental units. Choose the correct answer from the options given below :

  1. A-II, B-IV, C-I, D-III
  2. A-IV, B-II, C-I, D-III
  3. A-IV, B-I, C-II, D-III
  4. A-III, B-I, C-II, D-IV
Ques. 9JEE Main 2026, 5 April (Evening Shift)

In an experiment to determine the resistance of a given wire using Ohm's law, the voltmeter and ammeter readings are noted as 10 V and 5 A, respectively. The least counts of voltmeter and ammeter are 500 mV and 200 mA, respectively. The estimated error in the resistance measurement is .

  1. 0.25
  2. 2
  3. 2.5
  4. 0.18
Ques. 10JEE Main 2026, 4 April (Morning Shift)

In a screw gauge when the circular scale is given five complete rotations it moves linearly by 2.5 mm. If the circular scale has 100 divisions, the least count of screw gauge is mm.

  1. 1 10-2
  2. 1 10-3
  3. 5 10-2
  4. 5 10-3
Ques. 11JEE Main 2026, 2 April (Morning Shift)

The dimensional formula of 12 0 E2 ( 0 = permittivity of vacuum and E = electric field) is MaLbTc. The value of 2a-b+c= .

  1. 0
  2. 1
  3. -1
  4. 2

All Units and Measurements PYQs →

PDFDownload Units and Measurements PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All JEE Main Physics chapters