हिंदी

Frank solutions for Physics [English] Class 9 ICSE chapter 1 - Measurement [Latest edition]

Advertisements

Chapters

Frank solutions for Physics [English] Class 9 ICSE chapter 1 - Measurement - Shaalaa.com
Advertisements

Solutions for Chapter 1: Measurement

Below listed, you can find solutions for Chapter 1 of CISCE Frank for Physics [English] Class 9 ICSE.


Exercise 1Exercise 2Exercise 3Exercise 4Exercise 5
Exercise 1 [Pages 15 - 16]

Frank solutions for Physics [English] Class 9 ICSE 1 Measurement Exercise 1 [Pages 15 - 16]

Exercise 1 | Q 1 | Page 15

What is meant by measurement?

Exercise 1 | Q 2 | Page 15

Define a fundamental quantity.

Exercise 1 | Q 3 | Page 15

Name the three fundamental quantities.

Exercise 1 | Q 4 | Page 15

What do you mean by the term unit?

Exercise 1 | Q 5 | Page 15

Define standard meter.

Exercise 1 | Q 6 | Page 15

Name three systems of unit and state various fundamental units in them.

Exercise 1 | Q 7 | Page 15

Name the SI unit of mass and define it.

Exercise 1 | Q 8 | Page 15

Name three units of length which are bigger than a meter. How are they related to the meter?

Exercise 1 | Q 9 | Page 15

What are the fundamental units in SI system? Name them along with their symbols.

Exercise 1 | Q 10 | Page 15

What do you mean by light year?

Exercise 1 | Q 11 | Page 15

Exercise

Exercise 1 | Q 12 | Page 15

Which of the following is not a unit of distance?

  • Leap year

  • parsec

  • light year

  • Angstrom

Exercise 1 | Q 15.1 | Page 15

Complete the rollowing:
1 fermi __________ m

Exercise 1 | Q 15.2 | Page 15

Complete the rollowing:
1 m = ____ Å

Exercise 1 | Q 15.3 | Page 15

Complete the rollowing:
1 parsec= _____ ly

Exercise 1 | Q 15.4 | Page 15

Complete the rollowing:
1 light year= ________ m

Exercise 1 | Q 15.5 | Page 15

Complete the rollowing:
1 m = ____ μ.

Exercise 1 | Q 15.6 | Page 15

Complete the rollowing:
1 micron= ____ Å

Exercise 1 | Q 15.7 | Page 15

Complete the rollowing:
1 u = ____ kg

Exercise 1 | Q 16 | Page 15

State two units of mass smaller than a kilogram?

Exercise 1 | Q 17 | Page 15

What is a leap year?

Exercise 1 | Q 18 | Page 16

The Wavelength of a particular colour is 5400Å. Express it in nanometer and metre.

Exercise 1 | Q 19 | Page 16

The size of bacteria is 2 μ.. Find the number of bacteria in 3 m length.

Exercise 1 | Q 20.1 | Page 16

Complete the following: 1 quintal =………kg

Exercise 1 | Q 20.2 | Page 16

Complete the following : 1 mg =………kg

Exercise 1 | Q 20.3 | Page 16

Complete the following:

1 mean solar day = _______ s.

Exercise 1 | Q 20.4 | Page 16

Complete the following: 1 nano second =……….s.

Exercise 1 | Q 20.5 | Page 16

Complete the following: 1 year =……….s.

Exercise 2 [Pages 28 - 30]

Frank solutions for Physics [English] Class 9 ICSE 1 Measurement Exercise 2 [Pages 28 - 30]

Exercise 2 | Q 1 | Page 28
What do you mean by the term pitch of a screw gauge?
Exercise 2 | Q 2 | Page 28
Is pitch the same as least count?
Exercise 2 | Q 3 | Page 28
State two uses of vernire calipers.
Exercise 2 | Q 4 | Page 28
State two limitations of a metre rule.
Exercise 2 | Q 5.1 | Page 28

Explain the term pitch. How are they determined?

Exercise 2 | Q 5.2 | Page 28

Explain the term least count of a screw gauge. How are they determined?

Exercise 2 | Q 6 | Page 28
While measuring the volume of a piece of copper, it is found that the initial level of water in a graduated cylinder is 30 ml and on immersing the piece in water, the level of water rises to 50 ml. Find the volume of the piece of copper.
Exercise 2 | Q 7 | Page 29
Draw a neat labeled diagram of vernier calipers.
Exercise 2 | Q 8 | Page 29
What is the purpose of a ratchet in a screw gauge?
Exercise 2 | Q 9 | Page 29

What do you mean by zero error of a screw gauge? How is it accounted for?

Exercise 2 | Q 10 | Page 29
Name the two scales of a screw gauge.
Exercise 2 | Q 11.1 | Page 29

What is the backlash error?

Exercise 2 | Q 11.2 | Page 29

How the backlash error is avoided?

Exercise 2 | Q 12 | Page 29
How will you measure the diameter of a wire using a screw gauge?
Exercise 2 | Q 13 | Page 29

In the following figure, the pitch of the screw is 1 mm. Calculate:
(i) the least count of screw gauge and
(ii) the reading represented in the figure.

Exercise 2 | Q 14 | Page 29
Which of the following measures a small length to a high accuracy: metre scale, vernier calipers, screw gauge?
Exercise 2 | Q 15.1 | Page 29

Name the instrument which has the least count

 0.1 mm

Exercise 2 | Q 15.2 | Page 29

Name the instrument which has the least count

1 mm

Exercise 2 | Q 15.3 | Page 29

Name the instrument which has the least count

0.01 mm

Exercise 2 | Q 16.1 | Page 29

Name the measuring employed to measure the diameter of a needle.

Exercise 2 | Q 16.2 | Page 29

Name the measuring employed to measure the thickness of a paper.

Exercise 2 | Q 16.3 | Page 29

Name the measuring employed to measure the diameter of a pencil.

Exercise 2 | Q 17 | Page 29

While measuring the length of a rod with a vernier callipers, below shows the position of its scales. What is the length of the rod? 

Exercise 2 | Q 18 | Page 29
What do you mean by a positive zero error of a screw gauge? How will you calculate it?
Exercise 2 | Q 19 | Page 29
The pitch of a screw gauge is 0.5 mm and the head scale is divided into 100 parts. What is the least count of screw gauge?
Exercise 2 | Q 20 | Page 29
What do you mean by a negative zero error of a screw gauge? How will you calculate it?
Exercise 2 | Q 21.1 | Page 29

State whether the following statement is true or false by writing T/F against it.

The diameter of a wire can be measured more accurately by using vernier calipers than by a screw gauge.

  • True

  • False

Exercise 2 | Q 21.2 | Page 29

State whether the following statement is true or false by writing T/F against it.

The least count of a screw gauge can be lowered by increasing the number of divisions on its thimble.

  • True

  • False

Exercise 2 | Q 21.3 | Page 29

State whether the following statement is true or false by writing T/F against it.

A metre scale can measure a length of 6.346 cm.

  • True

  • False

Exercise 2 | Q 21.4 | Page 29

State whether the following statement is true or false by writing T/F against it.

The ratchet of a screw gauge is used to measure the depth of a beaker.

  • True

  • False

Exercise 2 | Q 21.5 | Page 29

State whether the following statement is true or false by writing T/F against it.

The metre scale, vernier calipers, and screw gauge are in decreasing order of least count.

  • True

  • False

Exercise 2 | Q 22 | Page 29
What do you mean by the term volume of a body?
Exercise 2 | Q 23 | Page 29
Is 1 cm3 the same as 1 ml?
Exercise 2 | Q 24 | Page 29

Express 1 liter in terms m3.

Exercise 2 | Q 25 | Page 30
How will you find the volume of an irregular solid (lighter than water) by displacement method?
Exercise 2 | Q 26 | Page 30
What is the SI unit of volume? How is it related to liter?
Exercise 2 | Q 27 | Page 30

A screw has a pitch equal to 0.5 mm. What should be the number of divisions on its head so as to read correctly up to 0.001 mm with its help?

Exercise 2 | Q 28 | Page 30

The following Figure shows the reading obtained while measuring the diameter of a wire using a screw gauge. The screw advances by 1 division on the main scale when the circular head is rotated once. Calculate:
(i) the pitch of the screw gauge,
(ii) Least count of the screw gauge, and

(iii) The diameter of the wire.

Exercise 2 | Q 29 | Page 30
State three precautions you would take while measuring the volume of an irregular solid lighter than water, using a measuring cylinder.
Exercise 2 | Q 30 | Page 30
How will you find the volume of a lump of salt or sugar using a graduated cylinder?
Exercise 3 [Page 38]

Frank solutions for Physics [English] Class 9 ICSE 1 Measurement Exercise 3 [Page 38]

Exercise 3 | Q 1 | Page 38
What do you mean by a simple pendulum?
Exercise 3 | Q 2 | Page 38

What is a seconds pendulum?

Exercise 3 | Q 3 | Page 38
Name a device used to measure the short intervals of time.
Exercise 3 | Q 4 | Page 38
Write the SI unit of frequency?
Exercise 3 | Q 5 | Page 38
Define one hertz.
Exercise 3 | Q 6 | Page 38
State the relation between frequency and time period.
Exercise 3 | Q 7.1 | Page 38

What do you mean by an oscillation?

Exercise 3 | Q 7.2 | Page 38

Is there any relation between oscillation and amplitude?

Exercise 3 | Q 8 | Page 38
Write the SI unit of amplitude.
Exercise 3 | Q 9 | Page 38
What is a seconds pendulum?
Exercise 3 | Q 10 | Page 38
Calculate the length of a seconds pendulum at a place where g = 9.8 ms-2.
Exercise 3 | Q 11 | Page 38

A person sitting on a swing stands up. The time period of swing:

  • Increases

  • decreases

  • Does not change

  • become zero

Exercise 3 | Q 12 | Page 38

Moon has no atmosphere and acceleration due to gravity at its surface is one-sixth that at the earth's surface. When a pendulum is taken from earth to moon surface, its time period will:

  •  Increase

  • decrease

  • Not change

  • becomes infinite.

Exercise 3 | Q 13 | Page 38
The time period of a pendulum is infinite. What will happen to its oscillation?
Exercise 3 | Q 14 | Page 38
What do you mean by the effective length of a simple pendulum?
Exercise 3 | Q 15 | Page 38
Draw a graph of l against T2 for a simple pendulum of length l and time period T for different values of l.
Exercise 3 | Q 16 | Page 38
Name the factors on which the time period of a simple pendulum depends. Write the formula for the time period in terms of the above named factors.
Exercise 3 | Q 17 | Page 38
Compare the time periods of a simple pendulum at places where g = 9.8 ms−2 and 4.36 ms−2 respectively.
Exercise 3 | Q 18 | Page 38
Does the time period of a simple pendulum depend on the mass of the bob?
Exercise 3 | Q 19 | Page 38
The time periods of two simple pendulums at a place are in the ratio 2:1. What will be the corresponding ratio of their lengths?
Exercise 3 | Q 20 | Page 38
What do you mean by mass? Name the instrument used to measure the mass of a body.
Exercise 3 | Q 21 | Page 38
What is the principle of a beam balance?
Exercise 3 | Q 22 | Page 38
State important precautions employed for measuring the mass of a body using a beam balance.
Exercise 3 | Q 23 | Page 38
Write the SI units of time and mass.
Exercise 3 | Q 24 | Page 38
What are the conditions for a beam balance to be true?
Exercise 4 [Page 44]

Frank solutions for Physics [English] Class 9 ICSE 1 Measurement Exercise 4 [Page 44]

Exercise 4 | Q 1 | Page 44
Define the least count of an instrument.
Exercise 4 | Q 2 | Page 44
What is the maximum possible error in the measurement of 1.80 cm?
Exercise 4 | Q 3 | Page 44
What do you mean by the slope of a graph?
Exercise 4 | Q 4.1 | Page 44

What is the least count in the case of the following instrument?

Metre scale

Exercise 4 | Q 4.2 | Page 44

What is the least count in the case of the following instrument?

vernier calipers

Exercise 4 | Q 4.3 | Page 44

What is the least count in the case of the following instrument?

Screw gauge

Exercise 4 | Q 5.1 | Page 44

What is the least count in the case of the following instrument?

Stopwatch

Exercise 4 | Q 5.2 | Page 44

What is the least count in the case of the following instrument?

Thermometer

Exercise 4 | Q 5.3 | Page 44

What is the least count in the case of the following instrument?

Spring balance

Exercise 4 | Q 6 | Page 44
'Each measuring instrument has a limit of accuracy'. Comment on the statement.
Exercise 4 | Q 7 | Page 44
Name two kinds of error in a measurement. How are they minimized?
Exercise 4 | Q 8 | Page 44

Which of the following measurement is most accurate?

  • 3000 g

  • 3.0 kg

  • 3.00 kg

  • 3 kg

Exercise 4 | Q 9 | Page 44

Is there any difference in the following measurements?

(a) 51.7 cm
(b) 51.70 cm
(c) 51.700 cm.

Explain your answer.
Which measurement is most accurate?

Exercise 5 [Pages 46 - 50]

Frank solutions for Physics [English] Class 9 ICSE 1 Measurement Exercise 5 [Pages 46 - 50]

Exercise 5 | Q 1 | Page 46
What is meant by a unit?
Exercise 5 | Q 2 | Page 46

What are the fundamental units?

Exercise 5 | Q 3 | Page 46
What are the derived units?
Exercise 5 | Q 4 | Page 46

Define standard meter.

Exercise 5 | Q 5 | Page 46
Define standard kilogram.
Exercise 5 | Q 6 | Page 46

Name the SI unit of electric current.

Exercise 5 | Q 7 | Page 47
Define the light year.
Exercise 5 | Q 8 | Page 47
Which is bigger: light year or parsec?
Exercise 5 | Q 9 | Page 47
Which is smaller: micron or Fermi?
Exercise 5 | Q 10 | Page 47
Define parsec. Is it the same as the Astronomical unit?
Exercise 5 | Q 11 | Page 47
What is the least count of your laboratory vernier calipers?
Exercise 5 | Q 12 | Page 47
What is the importance of a vernier scale?
Exercise 5 | Q 13 | Page 47

Define the least count of an instrument.

Exercise 5 | Q 14 | Page 47
Can we measure the thickness of a piece of paper by vernier calipers?
Exercise 5 | Q 15 | Page 47
How does the zero error arise in the instrument?
Exercise 5 | Q 16 | Page 47
Why is the screw gauge so named?
Exercise 5 | Q 17 | Page 47

Define the time period of a simple pendulum,

Exercise 5 | Q 18 | Page 47
How does the presentation of data in a tabular form help us in analyzing them? Explain with one example.
Exercise 5 | Q 19 | Page 47
Name the material used for making a screw gauge.
Exercise 5 | Q 20 | Page 47
Define the pitch of the screw gauge.
Exercise 5 | Q 21 | Page 47
How does negative error arise in the instrument?
Exercise 5 | Q 22 | Page 47
What is backlash error and how is it avoided?
Exercise 5 | Q 23 | Page 47
What is the difference between a nail and a screw?
Exercise 5 | Q 24 | Page 47
How many types of motions does a screw have?
Exercise 5 | Q 25 | Page 47
What is the unit for the least count of an instrument?
Exercise 5 | Q 26 | Page 47

Express micron in terms of meter.

Exercise 5 | Q 27 | Page 47
What is the principle of a physical balance?
Exercise 5 | Q 28 | Page 47

Express light year in terms of meter.

Exercise 5 | Q 29 | Page 47
Plot a graph between square of the time period (T2) and length (l) for a simple pendulum.
Exercise 5 | Q 30 | Page 47
Plot a graph between the time period (T) and length (l) for a simple pendulum.
Exercise 5 | Q 31 | Page 47
Is oscillation the same as vibration?
Exercise 5 | Q 32 | Page 47
What is the relation between frequency (f) and time period (T)?
Exercise 5 | Q 33 | Page 47
 What is an ideal simple pendulum?
Exercise 5 | Q 34 | Page 47
Does a wall clock run slow or fast in winter?
Exercise 5 | Q 35 | Page 47
Briefly, explain the need for measurements.
Exercise 5 | Q 36 | Page 47
Distinguish between fundamental and derived units.
Exercise 5 | Q 37 | Page 47
State the fundamental units of the SI system.
Exercise 5 | Q 38 | Page 47
What is the importance of maintaining the standard units?
Exercise 5 | Q 39 | Page 47
What are the main characteristics of a standard unit?
Exercise 5 | Q 40 | Page 47
What are the fundamental units? Name some of the fundamental units.
Exercise 5 | Q 41.1 | Page 47

Consider the following case where the zero of vernier scale and the zero of the main scale are clearly seen. If L.C. of the vernier calipers is 0.01 cm, write the zero error and zero correction of the following.

Exercise 5 | Q 41.2 | Page 47

Consider the following case where the zero of vernier scale and the zero of the main scale are clearly seen. If L.C. of the vernier calipers is 0.01 cm, write the zero error and zero correction of the following.

Exercise 5 | Q 41.3 | Page 47

Consider the following case where the zero of vernier scale and the zero of the main scale are clearly seen. If L.C. of the vernier calipers is 0.01 cm, write the zero error and zero correction of the following.

Exercise 5 | Q 42 | Page 47
A screw gauge has 50 divisions on its circular scale and the pitch of the screw is 0.5 mm. What us its least count?
Exercise 5 | Q 43 | Page 47
In the case of a vernier caliper, 1 MSD = 1 mm. If 10 VSD coincide with 9 MSD; what is its least count?
Exercise 5 | Q 44 | Page 48

What is the zero error of a screw gauge?

Exercise 5 | Q 45 | Page 48
If the 4th division of the circular scale coincides with the zero of the main scale of a screw gauge of least count 0.01 mm, what is it's zero error?
Exercise 5 | Q 46 | Page 48
If the 47th division of the circular scale coincides with the zero of the main scale of a screw gauge of least count 0.01 mm and having 50 circular divisions, what is it's zero error?
Exercise 5 | Q 47 | Page 48
We can find the diameter of a wire by wrapping it around a pencil and measuring the length of turns with the help of a meter scale. Is this approach more accurate than determining the diameter of the wire with the help of a screw gauge?
Exercise 5 | Q 48 | Page 48

The following figure shows the reading of a vernier caliper used for measuring the thickness of a metal sheet.
(i) Find the least count of the instrument.
(ii) Calculate the thickness of the metal sheet.

Exercise 5 | Q 49 | Page 48

What is meant by the pitch of a screw gauge? The pitch of a screw is 1 mm.
Find the reading of the instrument shown in the following figure.

Exercise 5 | Q 50 | Page 48
A screw thread has 20 threads in 1 cm and its circular scale has 50 divisions. Calculate its pitch and least count.
Exercise 5 | Q 51.1 | Page 48

Define the following terms with reference to a simple pendulum:

Oscillation

Exercise 5 | Q 51.2 | Page 48

Define the following terms with reference to a simple pendulum:

Time period

Exercise 5 | Q 51.3 | Page 48

Define the following terms with reference to a simple pendulum:

Frequency

Exercise 5 | Q 51.4 | Page 48

Define the following terms with reference to a simple pendulum:

Amplitude

Exercise 5 | Q 52 | Page 48

If a pendulum takes 0.5 s to travel from A to B as shown in the following figure, find its time period and frequency.

Exercise 5 | Q 53 | Page 48
A piece of metal has a mass of 540 g and a volume of 200 cm3. Calculate the density of the metal incorrect significant figures.
Exercise 5 | Q 54 | Page 48
An alloy is made by mixing 540 g of copper of density 9 g cm-3 with 240 g of iron of density 8 g cm-3. Find the density of the alloy assuming that the volume of each metal does not change during mixing.
Exercise 5 | Q 55 | Page 48

The following diagrams (Fig. 5) show the use of a vernier caliper under three different situations. Study the diagrams carefully and note down the vernier readings in each case.

(a) Measuring the diameter of the rod

(b) Measuring Internal diameter of a cavity

(c) Measuring depth of a cavity

Exercise 5 | Q 56.1 | Page 49
What is meant by measurement?
Exercise 5 | Q 56.2 | Page 49

 What are the fundamental units in the SI system? Name them along with their symbols.

Exercise 5 | Q 56.3 | Page 49

What are the rules observed while writing the unit of a physical quantity?

Exercise 5 | Q 57 | Page 49
Describe in steps, how would you use a vernier caliper to measure the length of a small rod?
Exercise 5 | Q 58 | Page 49
What is meant by zero error of a vernier caliper? How is it determined? Draw neat diagrams to explain it. How is it taken into account to get the correct measurement?
Exercise 5 | Q 59 | Page 49

Describe the procedure to measure the diameter of a wire with the help of a screw gauge.

Exercise 5 | Q 60 | Page 49
What is meant by zero error of a vernier caliper? How is it determined? Draw neat diagrams to explain it. How is it taken into account to get the correct measurement?
Exercise 5 | Q 61 | Page 49
How will you record your observations while measuring the volume of an irregular solid by the displacement method using a cylinder?
Exercise 5 | Q 62 | Page 49
How do you find the slope of a straight line obtained on a graph?
Exercise 5 | Q 63 | Page 49
A graph plotted by taking T2 on the Y-axis and L on the X-axis in an experiment of a simple pendulum is a straight line. What relationship between T2 and l, does this graph represent?
Exercise 5 | Q 64 | Page 49
How does the presentation of data in a tabular form help us in analyzing them? Explain with one example.
Exercise 5 | Q 65 | Page 49
Give a tabular format for recording the observations in an experiment of the simple pendulum while measuring the time period of the pendulum for its different lengths.
Exercise 5 | Q 66.1 | Page 49

Define the following terms with reference to a simple pendulum:

Oscillation

Exercise 5 | Q 66.2 | Page 49

Define the following terms with reference to a simple pendulum:

Amplitude

Exercise 5 | Q 66.3 | Page 49

Define the following terms with reference to a simple pendulum:

Frequency

Exercise 5 | Q 66.4 | Page 49

Define the terms : time period as related to a simple pendulum.

Exercise 5 | Q 67 | Page 49

Draw a neat diagram of a simple pendulum. Show on it the effective length of the pendulum and its one oscillation .

Exercise 5 | Q 68.1 | Page 50

What is a simple pendulum?

Exercise 5 | Q 68.2 | Page 50

Name the factors on which the time period of a simple pendulum depends. Write the relation for the time period in terms of the above named factors.

Exercise 5 | Q 69.1 | Page 50

Show how will you use the physical balance to measure the mass of an object.

Exercise 5 | Q 69.2 | Page 50

Mention three precautions that you would observe to measure the mass of a body using a beam balance.

Exercise 5 | Q 69.3 | Page 50

 State two conditions for a beam balance to be true.

Exercise 5 | Q 70 | Page 50
In an experiment of a simple pendulum, time for 20 oscillations of the pendulum of a given length is measured and recorded as 40 s, 41 s, 42 s, 39 s, and 38 s. Find the absolute error in each measurement.

Solutions for 1: Measurement

Exercise 1Exercise 2Exercise 3Exercise 4Exercise 5
Frank solutions for Physics [English] Class 9 ICSE chapter 1 - Measurement - Shaalaa.com

Frank solutions for Physics [English] Class 9 ICSE chapter 1 - Measurement

Shaalaa.com has the CISCE Mathematics Physics [English] Class 9 ICSE CISCE solutions in a manner that help students grasp basic concepts better and faster. The detailed, step-by-step solutions will help you understand the concepts better and clarify any confusion. Frank solutions for Mathematics Physics [English] Class 9 ICSE CISCE 1 (Measurement) include all questions with answers and detailed explanations. This will clear students' doubts about questions and improve their application skills while preparing for board exams.

Further, we at Shaalaa.com provide such solutions so students can prepare for written exams. Frank textbook solutions can be a core help for self-study and provide excellent self-help guidance for students.

Concepts covered in Physics [English] Class 9 ICSE chapter 1 Measurement are Unit Systems, International System of Units (Si System), Vernier Callipers, Simple Pendulum for Time, Measurements Using Common Instruments, Measurements, Physical Quantities, Unit and Its Types, Unit Prefixes, Measuring Smaller Distances, Measuring Larger Distances, Measurement of Time, Rules and Conventions for Writing SI Units and Their Symbols, Principle of Vernier, Screw Gauge, Principle of Screw Gauge, A Time Period of Oscillation and Frequency, Measurement of Length, Measurement of Mass.

Using Frank Physics [English] Class 9 ICSE solutions Measurement exercise by students is an easy way to prepare for the exams, as they involve solutions arranged chapter-wise and also page-wise. The questions involved in Frank Solutions are essential questions that can be asked in the final exam. Maximum CISCE Physics [English] Class 9 ICSE students prefer Frank Textbook Solutions to score more in exams.

Get the free view of Chapter 1, Measurement Physics [English] Class 9 ICSE additional questions for Mathematics Physics [English] Class 9 ICSE CISCE, and you can use Shaalaa.com to keep it handy for your exam preparation.

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×