Get Answers to all your Questions

header-bg qa

The resistance R of a wire is given by relation   R=\rho l / \pi r^{2} . Percentage error in the measurement of \rho, l and r is 1%, 2% and 3% respectively. Then the percentage error in the measurement of R is
 

  • Option 1)

    6%

  • Option 2)

    9%

  • Option 3)

    8%

  • Option 4)

    10%

 

Answers (1)

best_answer

As we learnt in 

Percentage error in the value of x -

x= \frac{\left ( \Delta a+\Delta b \right )}{a+b}\times 100%

- wherein

\Delta a= absolute error in measurement of a

\Delta b= absolute error in measurement of b

\Delta x= absolute error in measurement of x

 

 R=\frac{ \rho l}{\pi r^{2}}

\frac{\Delta R}{R}\times 100 =\left ( \frac{\Delta \rho}{\rho}+\frac{\Delta l}{l}+\frac{2\Delta r}{r} \right ) \times 100

=(1+2+2\times3)\times100

=(3+6)\times 100=9\%

 


Option 1)

6%

Option is incorrect

Option 2)

9%

Option is correct

Option 3)

8%

Option is incorrect

Option 4)

10%

Option is incorrect

Posted by

Plabita

View full answer