Short answer type questions (3marks) of Physical World And Measurements

Q1. If E,M,J and G respectively denote energy, mass, angular momentum and gravitational constant, Calculate the dimensions of EJ2 /M5G2
Q2. The frequency of vibration of stretched string depends on its length L its mass per unit length m and the tension T in the string obtain dimensionally an expression for frequency .

Q3. What is meant by significant figures .State the rules for counting the number of significant figures in a measured quantity?
Q4. A physical quantity X is given by X = A
2B3/CD , If the percentage errors of measurement in A,B,C and D are 4%,2%,3% and 1% respectively, then calculate the % error in X.

Q5. If two resistors of resistance R1=(4 ± 0.5)and R2=(16 ± 0.5)are connected (1) In series and (2) Parallel . Find the equivalent resistance in each case with limits of % error.
Q6. The length of a rod measured in an experiment was found to be 2.48m, 2.46, 2.50m and 2.48m and 2.49m, Find the average length , the absolute error in each observation and % error.

Q7. A famous relation in physics relates moving mass m to the rest mass m0 of a particle in terms of its speed v and the speed of the light c. A boy recalls the relation almost correctly but forgets where to put the constant c. He writes:

m = mo / (1 v2)1/2 Guess where to put the missing c.