Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas JEE Main2020PhysicsUnits and DimensionsPractice

The period of oscillation of a simple pendulum is given by T = 2 π L g , where L is the length of the pendulum and g is the acceleration due to gravity. The length is measured using a meter scale which has 500 divisions. If the measured value L is 50 cm , the accuracy in the determination of g is 1.1 % and the time taken for 100 oscillations is 100 seconds, what should be the possible error in measurement of the cloc

Options

  1. A1
  2. B2
  3. C5
  4. D0.25

Correct answer

C. 5

Step-by-step solution

Given, T = 2 π l g or T 2 = 4 π 2 l g ∴     2 ∆ T T = ∆ l l + ∆ g g ...(i) Now, l = 50   cm ,   ∆ l = 2   mm = 0.2   cm ∆ g g = 1.1 % = 1.1 100 Put these values in Equation. (i), then we get ∆ T T = 1 2 0.2 50 + 1.1 100 = 7.5 × 10 - 3   s or 7. 5   ms ∵ In 100 s, resolution of the clock is 7 .5   ms . ∴ In 60 s resolution of the clock is 7 .5 × 60 100 ≈ 5   ms

Practice Units and Dimensions on Quantrex Academy →

More from Units and Dimensions

In a new system of units, the units of mass, length, time and current are 5 kg, 5 m, 5 s and 5 A, respectively. If ₀ and ₀ are the permeability and permittivity of free space, resp 2026A new unit ( ) of length is chosen such that it is equal to the speed of light in vacuum. What is the distance between Venus and Earth in terms of units if light takes 6 min. 40 s 2026Consider the equation H = x^p ^q E^r t^s , where H= magnetic field; E= electric field, = permittivity, x= distance, t= time. The values of p, q, r and s respectively are: 2026The percentage error in the calculated volume of a sphere, if there is 2 % error in its diameter measurement, is __________. 2026Match List - I with List - II. List - I List - II A. Boltzmann constant I. [M⁻¹L^3T⁻²] B. Stefan's constant II. [ML^2T⁻¹] C. Planck's constant III. [ML^2T⁻²K⁻¹] D. Gravitational co 2026The potential energy of a particle changes with distance x from a fixed origin as V = A x x + B , where A and B are constant with appropriate dimensions. The dimensions of AB are _ 2026Match List-I with List-II. List-I List-II A. Meter (L) I. hc G B. Second (S) II. Gh c^5 C. Kilogram (M) III. K^2L^2c^3 Gh D. Kelvin (K) IV. Gh c^3 where h (Planck's constant), G (g 2026L , C and R represents physical quantities inductance, capacitance and resistance respectively. The dimensional formula ML^2 T⁻⁴ A⁻² corresponds to __________. 2026 Full Units and Dimensions list All NTA Abhyas JEE Main PYQs