Daily Practice Problems
Class 11 Physics
Units and Measurements Question 1.

What do you understand by the ‘Fundamental units’ and ‘Derived units’?

Question 2.

Name different systems of units for measurement.

Question 3.

What is the parallax method? Explain.

Question 4.

How many metres in 2 light years?

Question 5.

Fill in the blanks:

1. 1 fermi = _ m.
2. 1 astronomical unit = _m.
3. 1 angstrom = _m.
4. 1 parsec = _m.

Question 6.

What do you understand by the unified atomic mass unit (u)?

Question 7.

Define the terms: accuracy and precision.

Question 8.

Differentiate between systematic errors and random errors.

Question 9.

What do you understand by ‘Least count error’?

Question 10.

What do you understand by the terms ‘Absolute error’, ‘Relative error’ and ‘Percentage error’?

Question 11.

The resistance R=V/I, where V= (100±4) V and I= (100±3) A. Find the percentage error in R.

Question 12.

The length and breadth of a rectangular park is 3.21 m. and 4.278 m. respectively. What is the area of that park to appropriate significant figures?

Question 13.

How do you define ‘the dimensions of the quantity’? Write down the dimensional formula for work and force.

Question 14.

State the number of significant figures in the following:

1. 0.0008 m2.
2. 3.19×1035kg.

Question 15.

A physical quantity A is related to four observables p, q, r and s as follows:

A = p4q2r3/s3

The percentage errors of measurement in p, q, r, s is 2%, 4%, 1% and 3% respectively. What is the percentage error in the quantity A?

Question 16.

There are two boxes of masses 30.17 g. and 3.20 kg. respectively. Give the total mass of these two boxes to the correct significant figures.

Question 17.

The third equation of motion is: v2=u2+2as.

Check if it is dimensionally correct or not.

Question 18.

Write down the dimensional formula for Volume, Speed and Mass Density.

Question 19.

What are the seven base quantities? Make a table for their name and symbols.

Question 20.

Is ‘amount of substance’ a fundamental quantity? Define it. What is its symbol?

Question 21.

The period of oscillation of a simple pendulum is T=2∏√L/√g. Measured value of L is 25.0cm. known to 1mm. accuracy and time for 100 oscillations of the pendulum is found to be 80 sec. using a wrist watch of 1s resolution. What is the accuracy in the determination of g?

Question 22.

Each side of a cube is measured to be 6.534m. What are the total surface area and the volume of the cube to appropriate significant figures?

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