1- Distinguish between accuracy and precision. 2
2- Check weather the equation 1/2mv2 = mgh is dimensionally correct. 2
3 Give the dimension of following physical quantities.
a) Density b)Force c)Power d)Energy 2
4- Distinguish between absolute error and relative error. 2
5- If displacement of a body s= (200±5) m and time taken by it t= (20±0.2) s, then find the percentage error in the calculation of velocity 3
6 Each of the following equations was given by a student during an examination.
a)1/2mv2=1/2mv2+m2 gh
b)v=u+at2
c)ma=v2
Do the dimensional analysis of each equation and explain why the equations cannot be correct 3
7 The measured quantity a, b ,c and x is calculated by using the relation x=ab2/c3.If the percentage errors in measurement of a, b and c are 4%,2% and 7%, calculate maximum percentage error in value of x obtained. 3
8 Radhika ,Supriya and Hema were asked to find the mass of a metal piece independently one by one using the same balance and same weight box. Each student was asked to take three observations. The students reported their result as shown in the following table:
Students Result reported Average
I II III
Radikha 1.325 1.326 1.325 1.325
Supriya 1.310 1.311 1.321 1.314
Hema 1.31 1.30 1.31 1.31
If the actual mass of the metal piece is 1.325g and the permitted uncertainty in the measurement is 0.001g, answer the following questions:
(i) Whose measurement is both accurate and precise? Justify your answer.
(ii) Whose measurement is precise and not accurate Justify your answer?
(iii) Whose measurements are neither accurate nor precise? Justify your 3