Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Units and Measurement question

2024 · Q163
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /NEET
  3. /Physics
  4. /Units and Measurement
  5. /2024 · Q163

Units and Measurement question

2024 · Q163

NEETPhysicsUnits and MeasurementMCQ+4 / −1

In an electrical circuit, the voltage is measured as V=(200±4)V=(200 \pm 4)V=(200±4) volt and the current is measured as I=(20±0.2)I=(20 \pm 0.2)I=(20±0.2) A. The value of the resistance is:

  1. A
    (10±4.2)Ω(10 \pm 4.2) \Omega(10±4.2)Ω
  2. B
    (10±0.3)Ω(10 \pm 0.3) \Omega(10±0.3)Ω
  3. C
    (10±0.1)Ω(10 \pm 0.1) \Omega(10±0.1)Ω
  4. D
    (10±0.8)Ω(10 \pm 0.8) \Omega(10±0.8)Ω
View written solutionFree

Correct answer: B

To determine the resistance $R$ using Ohm's law, we use the formula:

$R = \frac{V}{I}$

Given:

$V = (200 \pm 4)$ volts

$I = (20 \pm 0.2)$ amperes

First, calculate the nominal value of the resistance:

$$R = \frac{200}{20} = 10 \, \Omega$$

Next, we need to calculate the uncertainty in the resistance. For division, the relative uncertainties add up. The relative uncertainty for voltage is:

$$\frac{\Delta V}{V} = \frac{4}{200} = 0.02$$

and for current:

$$\frac{\Delta I}{I} = \frac{0.2}{20} = 0.01$$

Adding these relative uncertainties gives us the relative uncertainty for the resistance:

$$\frac{\Delta R}{R} = \frac{\Delta V}{V} + \frac{\Delta I}{I} = 0.02 + 0.01 = 0.03$$

Now, we calculate the absolute uncertainty for the resistance:

$$\Delta R = R \times 0.03 = 10 \times 0.03 = 0.3 \, \Omega$$

Therefore, the resistance with its uncertainty is:

$$R = 10 \pm 0.3 \, \Omega$$

Thus, the correct answer is:

Option B $(10 \pm 0.3) \Omega$

PreviousNext

More from Units and Measurement

  • The pitch of an error free screw gauge is 1 mm and there are 100 divisions on the circular scale. While measuring the diameter of a thick wire, the pitch scale reads 1 mm and 63rd  division on the…2024 · MCQ
  • The potential energy of a particle moving along x-direction varies as V=x​+BAx2​. The dimensions of BA2​ are:2024 · MCQ
  • The diameter of a spherical bob, when measured with vernier callipers yielded the following values : 3.33 cm,3.32 cm,3.34 cm,3.33 cm and 3.32 cm. The mean diameter to appropriate…2023 · MCQ
  • The mechanical quantity, which has dimensions of reciprocal of mass (M−1) is :2023 · MCQ
  • The errors in the measurement which arise due to unpredictable fluctuations in temperature and voltage supply are :2023 · MCQ
  • A metal wire has mass (0.4±0.002) g, radius (0.3±0.001) mm and length (5±0.02) cm. The maximum possible percentage error in the measurement of density will nearly be :2023 · MCQ
  • The physical quantity that has the same dimensional formula as pressure is2022 · MCQ
  • The percentage error in the measurement of g is : (Given that g=T24π2L​, L=(10±0.1) cm, T=(100±1) s)2022 · MCQ