NCERT Solutions for Exercise 3.4 Class 12 Maths Chapter 3 - Matrices

NCERT Solutions for Exercise 3.4 Class 12 Maths Chapter 3 - Matrices

Edited By Ramraj Saini | Updated on Dec 03, 2023 03:51 PM IST | #CBSE Class 12th

NCERT Solutions For Class 12 Maths Chapter 3 Exercise 3.4

NCERT Solutions for Exercise 3.4 Class 12 Maths Chapter 3 Matrices are discussed here. These NCERT solutions are created by subject matter expert at Careers360 considering the latest syllabus and pattern of CBSE 2023-24. In the NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4, you will get questions related to elementary operation on the matrix. Elementary operations or transformations are a set of operations that are allowed to perform on the matrix to get transformed matrix. These transformations are useful in the finding inverse of a matrix if exists. If the inverse of a matrix exists then it is called an invertible matrix. There are some questions in exercise 3.4 Class 12 Maths where you need to find the inverse of a matrix using elementary operation. NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4 is very important as generally one question is directly asked from this exercise in the CBSE board final exam. Class 12 maths ch 3 ex 3.4 required more practice and the chances of silly mistakes are more here, so you must practice all the questions in order to get them correct in the board exam.

12th class Maths exercise 3.4 answers are designed as per the students demand covering comprehensive, step by step solutions of every problem. Practice these questions and answers to command the concepts, boost confidence and in depth understanding of concepts. Students can find all exercise together using the link provided below.

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Assess NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4

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Matrices Exercise: 3.4

Question 1 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix}1&-1\\2&3 \end{bmatrix}

Answer:

Use the elementary transformation we can find the inverse as follows

A=\begin{bmatrix}1&-1\\2&3 \end{bmatrix}

A=IA

\Rightarrow \begin{bmatrix}1&-1\\2&3 \end{bmatrix} = \begin{bmatrix}1&0\\0&1 \end{bmatrix}A

R_2\rightarrow R_2-2R_1

\Rightarrow \begin{bmatrix}1&-1\\0&5 \end{bmatrix} = \begin{bmatrix}1&0\\-2&1 \end{bmatrix}A

R_2\rightarrow \frac{R_2}{5}

\Rightarrow \begin{bmatrix}1&-1\\0&1 \end{bmatrix} = \begin{bmatrix}1&0\\\frac{-2}{5}&\frac{1}{5} \end{bmatrix}A

R_1\rightarrow R_1+R_2

\Rightarrow \begin{bmatrix}1&0\\0&1 \end{bmatrix} = \begin{bmatrix}\frac{3}{5}&\frac{1}{5}\\\frac{-2}{5}&\frac{1}{5} \end{bmatrix}A

\therefore A^{-1}= \begin{bmatrix}\frac{3}{5}&\frac{1}{5}\\\frac{-2}{5}&\frac{1}{5} \end{bmatrix}

Question 2 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix} 2&1\\1&1\end{bmatrix}

Answer:

A=\begin{bmatrix} 2&1\\1&1\end{bmatrix}

A=IA

\Rightarrow \begin{bmatrix} 2&1\\1&1\end{bmatrix} = \begin{bmatrix}1&0\\0&1 \end{bmatrix}A

R_1\rightarrow R_1-R_2

\Rightarrow \begin{bmatrix}1&0\\1&1 \end{bmatrix} = \begin{bmatrix}1&-1\\0&1 \end{bmatrix}A

R_2\rightarrow R_2-R_1

\Rightarrow \begin{bmatrix}1&0\\0&1 \end{bmatrix} = \begin{bmatrix}1&-1\\-1& 2 \end{bmatrix}A

A^{-1}= \begin{bmatrix}1&-1\\-1& 2 \end{bmatrix}

Thus we have obtained the inverse of the given matrix through elementary transformation

Question 7 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix} 3 & 1\\ 5 & 2 \end{bmatrix}

Answer:

A=\begin{bmatrix} 3 & 1\\ 5 & 2 \end{bmatrix}

A=IA

\Rightarrow \begin{bmatrix} 3 & 1\\ 5 & 2 \end{bmatrix} = \begin{bmatrix}1&0\\0&1 \end{bmatrix}A

R_2\rightarrow R_2-R_1

\Rightarrow \begin{bmatrix} 3 & 1\\ 2 & 1 \end{bmatrix} = \begin{bmatrix}1&0\\-1&1 \end{bmatrix}A

\Rightarrow R_1\rightarrow R_1-R_2

\Rightarrow \begin{bmatrix} 1 & 0\\ 2 & 1 \end{bmatrix} = \begin{bmatrix}2&-1\\-1&1 \end{bmatrix}A

R_2\rightarrow R_2-2R_1

\Rightarrow \begin{bmatrix} 1 & 0\\ 0 & 1 \end{bmatrix} = \begin{bmatrix}2&-1\\-5&3 \end{bmatrix}A

\therefore A^{-1}= \begin{bmatrix}2&-1\\-5&3 \end{bmatrix}.

Thus the inverse of matrix A is obtained using elementary transformation.

Question 8 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix} 4 &5 \\ 3 & 4 \end{bmatrix}

Answer:

A=\begin{bmatrix} 4 &5 \\ 3 & 4 \end{bmatrix}

A=IA

\Rightarrow\begin{bmatrix} 4 &5 \\ 3 & 4 \end{bmatrix}= \begin{bmatrix}1&0\\0&1 \end{bmatrix}A

R_1\rightarrow R_1-R_2

\Rightarrow\begin{bmatrix} 1 &1 \\ 3 & 4 \end{bmatrix}= \begin{bmatrix}1&-1\\0&1 \end{bmatrix}A

\Rightarrow R_2\rightarrow R_2-3R_1

\Rightarrow \begin{bmatrix}1&1\\0&1 \end{bmatrix} = \begin{bmatrix}1&-1\\-3&4 \end{bmatrix}A

R_1\rightarrow R_1-R_2

\Rightarrow \begin{bmatrix}1&0\\0&1 \end{bmatrix} = \begin{bmatrix}4&-5\\-3&4 \end{bmatrix}A

Thus using elementary transformation inverse of A is obtained as

\therefore A^{-1}=\begin{bmatrix}4&-5\\-3&4 \end{bmatrix}.

Question 9 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix} 3 & 10\\ 2 & 7 \end{bmatrix}

Answer:

A=\begin{bmatrix} 3 & 10\\ 2 & 7 \end{bmatrix}

A=IA

\Rightarrow\begin{bmatrix} 3 & 10\\ 2 & 7 \end{bmatrix}= \begin{bmatrix}1&0\\0&1 \end{bmatrix}A

R_1\rightarrow R_1-R_2

\Rightarrow\begin{bmatrix} 1& 3\\ 2 & 7 \end{bmatrix}= \begin{bmatrix}1&-1\\0&1 \end{bmatrix}A

\Rightarrow R_2\rightarrow R_2-2R_1

\Rightarrow\begin{bmatrix} 1& 3\\ 0 & 1 \end{bmatrix}= \begin{bmatrix}1&-1\\-2&3 \end{bmatrix}A

R_1\rightarrow R_1-3R_2

\Rightarrow\begin{bmatrix} 1& 0\\ 0 & 1 \end{bmatrix}= \begin{bmatrix}7&-10\\-2&3 \end{bmatrix}A

Thus using elementary transformation the inverse of A is obtained as

\therefore A^{-1}=\begin{bmatrix}7&-10\\-2&3 \end{bmatrix}.

Question 10 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix} 3 & -1\\ -4 & 2 \end{bmatrix}

Answer:

A=\begin{bmatrix} 3 & -1\\ -4 & 2 \end{bmatrix}

A=IA

\Rightarrow\begin{bmatrix} 3 & -1\\ -4 & 2 \end{bmatrix}= \begin{bmatrix}1&0\\0&1 \end{bmatrix}A

R_2\rightarrow R_2+R_1

\Rightarrow\begin{bmatrix} 3 & -1\\ -1 & 1 \end{bmatrix}= \begin{bmatrix}1&0\\1&1 \end{bmatrix}A

\Rightarrow R_1\rightarrow R_1+2R_2

\Rightarrow\begin{bmatrix} 1 & 1\\ -1 & 1 \end{bmatrix}= \begin{bmatrix}3&2\\1&1 \end{bmatrix}A

R_2\rightarrow R_2+R_1

\begin{bmatrix} 1 & 1\\ 0 & 2 \end{bmatrix}= \begin{bmatrix}3&2\\4&3 \end{bmatrix}A

R_2\rightarrow \frac{R_2}{2}

\begin{bmatrix} 1 & 1\\ 0 & 1 \end{bmatrix}= \begin{bmatrix}3&2\\2&\frac{3}{2} \end{bmatrix}A

R_1\rightarrow R_1-R_2

\begin{bmatrix} 1 & 0\\ 0 & 1 \end{bmatrix}= \begin{bmatrix}1&\frac{1}{2}\\2&\frac{3}{2} \end{bmatrix}A

\therefore A^{-1}=\begin{bmatrix}1&\frac{1}{2}\\2&\frac{3}{2} \end{bmatrix}.

Thus the inverse of A is obtained using elementary transformation.

Question 11 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix} 2 & -6\\ 1 & -2 \end{bmatrix}

Answer:

A=\begin{bmatrix} 2 & -6\\ 1 & -2 \end{bmatrix}

A=IA

\Rightarrow\begin{bmatrix} 2 & -6\\ 1 & -2 \end{bmatrix}= \begin{bmatrix}1&0\\0&1 \end{bmatrix}A

R_1\rightarrow R_1-3R_1

\Rightarrow\begin{bmatrix} -1 & 0\\ 1 & -2 \end{bmatrix}= \begin{bmatrix}1&-3\\0&1 \end{bmatrix}A

\Rightarrow R_2\rightarrow R_2+R_1

\Rightarrow\begin{bmatrix} -1 & 0\\ 0 & -2 \end{bmatrix}= \begin{bmatrix}1&-3\\1&-2 \end{bmatrix}A

R_1\rightarrow -R_1

\Rightarrow\begin{bmatrix} 1 & 0\\ 0 & -2 \end{bmatrix}= \begin{bmatrix}-1&3\\1&-2 \end{bmatrix}A

R_2\rightarrow \frac{R_2}{-2}

\Rightarrow\begin{bmatrix} 1 & 0\\ 0 & 1 \end{bmatrix}= \begin{bmatrix}-1&3\\\frac{1}{-2}&1 \end{bmatrix}A

thus the inverse of matrix A is

\therefore A^{-1}=\begin{bmatrix}-1&3\\\frac{1}{-2}&1 \end{bmatrix}.

Question 12 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix} 6 & -3\\ -2 & 1 \end{bmatrix}

Answer:

A=\begin{bmatrix} 6 & -3\\ -2 & 1 \end{bmatrix}

A=IA

\Rightarrow \begin{bmatrix} 6 & -3\\ -2 & 1 \end{bmatrix} = \begin{bmatrix}1&0\\0&1 \end{bmatrix}A

R_1\rightarrow \frac{R_1}{6}

\Rightarrow \begin{bmatrix} 1& -\frac{1}{2}\\ -2 & 1 \end{bmatrix} = \begin{bmatrix}\frac{1}{6}&0\\0&1 \end{bmatrix}A

\Rightarrow R_2\rightarrow R_2+2R_1

\Rightarrow \begin{bmatrix} 1& -\frac{1}{2}\\ 0 & 0 \end{bmatrix} = \begin{bmatrix}\frac{1}{6}&0\\\frac{1}{3}&1 \end{bmatrix}A

Hence, we can see all the zeros in the second row of the matrix in L.H.S so A^{-1} does not exist.

Question 14 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix} 2 & 1\\ 4 & 2 \end{bmatrix}

Answer:

A=\begin{bmatrix} 2 & 1\\ 4 & 2 \end{bmatrix}

A=IA

\Rightarrow\begin{bmatrix} 2 & 1\\ 4 & 2 \end{bmatrix}= \begin{bmatrix}1&0\\0&1 \end{bmatrix}A

R_2\rightarrow \frac{R_2}{2}

\Rightarrow\begin{bmatrix} 2 & 1\\ 2 & 1 \end{bmatrix}= \begin{bmatrix}1&0\\0&\frac{1}{2} \end{bmatrix}A

\Rightarrow R_1\rightarrow R_1-R_2

\Rightarrow\begin{bmatrix} 0 & 0\\ 2 & 1 \end{bmatrix}= \begin{bmatrix}1&\frac{-1}{2}\\0&\frac{1}{2} \end{bmatrix}A

Hence, we can see all upper values of matirix are zeros in L.H.S so A^{-1} does not exists.

Question 16 Using elementary transformations, find the inverse of each of the matrices, if it exists
in Exercises 1 to 17.

\begin{bmatrix} 1 &3 & -2\\ -3& 0 &-5 \\ 2 & 5 & 0 \end{bmatrix}

Answer:

A=\begin{bmatrix} 1 &3 & -2\\ -3& 0 &-5 \\ 2 & 5 & 0 \end{bmatrix}

A=IA

\Rightarrow\begin{bmatrix} 1 &3 & -2\\ -3& 0 &-5 \\ 2 & 5 & 0 \end{bmatrix}= \begin{bmatrix}1&0&0\\0&1&0 \\0&0&1 \end{bmatrix}A

R_2\rightarrow R_2+3R_1 and R_3\rightarrow R_3-2R_1

\Rightarrow\begin{bmatrix} 1 &3 & -2\\ 0& 9 &-11 \\ 0 & -1 & 4 \end{bmatrix}= \begin{bmatrix}1&0&0\\3&1&0 \\-2&0&1 \end{bmatrix}A

R_1\rightarrow R_1+3R_3 and R_2\rightarrow R_2+8R_3

\Rightarrow\begin{bmatrix} 1 &0 & 10\\ 0& 1 &21 \\ 0 & -1 & 4 \end{bmatrix}= \begin{bmatrix}-5&0&3\\-13&1&8 \\-2&0&1 \end{bmatrix}A

\Rightarrow R_3\rightarrow R_3+R_2

\Rightarrow\begin{bmatrix} 1 &0 & 10\\ 0& 1 &21 \\ 0 & 0 & 25 \end{bmatrix}= \begin{bmatrix}-5&0&3\\-13&1&8 \\-15&1&9 \end{bmatrix}A

R_3\rightarrow \frac{R_3}{25}

\Rightarrow\begin{bmatrix} 1 &0 & 10\\ 0& 1 &21 \\ 0 & 0 & 1 \end{bmatrix}= \begin{bmatrix}-5&0&3\\-13&1&8 \\-\frac{3}{5}&\frac{1}{25}&\frac{9}{25} \end{bmatrix}A

R_1\rightarrow R_1-10R_3 and R_2\rightarrow R_2-21R_3

\Rightarrow\begin{bmatrix} 1 &0 & 0\\ 0& 1 &0 \\ 0 & 0 & 1 \end{bmatrix}= \begin{bmatrix}1&\frac{-2}{5}&\frac{-3}{5}\\\frac{-2}{5}&\frac{4}{25}&\frac{11}{25} \\-\frac{3}{5}&\frac{1}{25}&\frac{9}{25} \end{bmatrix}A

Thus the inverse of three by three matrix A is

\therefore A^{-1}=.\begin{bmatrix}1&\frac{-2}{5}&\frac{-3}{5}\\\frac{-2}{5}&\frac{4}{25}&\frac{11}{25} \\-\frac{3}{5}&\frac{1}{25}&\frac{9}{25} \end{bmatrix}.

Question:18 Matrices A and B will be inverse of each other only if

(A) AB = BA

(B) AB = BA = 0

(C) AB = 0, BA = I

(D) AB = BA = I

Answer:

We know that if A is a square matrix of order n and there is another matrix B of same order n, such that AB=BA=I, then B is inverse of matrix A.

In this case, it is clear that A is inverse of B.

Hence, matrices A and B will be inverse of each other only if AB=BA=I.

Option D is correct.

More about NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4:-

In Class 12th Maths chapter 3 exercise 3.4, there are 18 questions out of which 17 questions are related to finding the inverse of a matrix using elementary operations if exists. One multiple choice type question is related to the condition of an invertible matrix. There are 3 solved examples and some theorems given before the NCERT text book exercise 3.4 Class 12 Maths. Examples related to finding the inverse of a matrix are also given in Class 12 Maths ch 3 ex 3.4. Theorems given in the NCERT syllabus are important to get conceptual clarity.

Also Read| Matrices Class 12 Maths Chapter Notes

Benefits of NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4:-

  • Class 12 Maths chapter 3 exercise 3.4 solutions are helpful for the students in the board exams as well as in competitive exams.
  • NCERT problems are solved by experts who have good knowledge and experience so you can rely upon them.
  • NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4 are beneficial for the students who are not able to solve some difficult problems.
  • Students are advised to solve all the NCERT problems including examples as most of the questions in the board exams are directly asked from the NCERT textbook.
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Key Features Of NCERT Solutions for Exercise 3.4 Class 12 Maths Chapter 3

  • Comprehensive Coverage: The solutions encompass all the topics covered in ex 3.4 class 12, ensuring a thorough understanding of the concepts.
  • Step-by-Step Solutions: In this class 12 maths ex 3.4, each problem is solved systematically, providing a stepwise approach to aid in better comprehension for students.
  • Accuracy and Clarity: Solutions for class 12 ex 3.4 are presented accurately and concisely, using simple language to help students grasp the concepts easily.
  • Conceptual Clarity: In this 12th class maths exercise 3.4 answers, emphasis is placed on conceptual clarity, providing explanations that assist students in understanding the underlying principles behind each problem.
  • Inclusive Approach: Solutions for ex 3.4 class 12 cater to different learning styles and abilities, ensuring that students of various levels can grasp the concepts effectively.
  • Relevance to Curriculum: The solutions for class 12 maths ex 3.4 align closely with the NCERT curriculum, ensuring that students are prepared in line with the prescribed syllabus.

Also see-

NCERT solutions of class 12 subject wise

Subject wise NCERT Exampler solutions

Happy learning!!!

Frequently Asked Questions (FAQs)

1. If a matrix A = [ 1 2 3] then order of matrix A ?

The order of matrix A is 1x3.

2. What of the definition of elements in a matrix ?

The numbers or functions that exist in the rows and columns of a particular matrix are called elements of the matrix. Definitions, examples and questions are given in the NCERT book. For more practice problems NCERT exemplar for class 12 Maths can be used. Practice class 12 ex 3.4 to command the concepts.

3. write some types of matrix ?

A square matrix, zero or null matrix, scalar matrix, diagonal matrix,  row matrix, and column matrix are some types of matrices.

4. Two matrices A and B are inverse of each other only if ?

If AB = BA = I, then A and B are inverses of each other.

5. What is the condition for addition of two matrices ?

The order of matrices has to be the same in order to add them.

6. Can we add matrix A of order 2x3 and matrix B of 3x2 ?

No, as the order of both the matrices are not the same.

7. Can we multiply matrix A of order 2x3 and matrix B of 3x2 ?

Yes, matrices A and B can be multiplied

8. What is order of the matrix we get when we multiply matrix A of order 2x3 and matrix B of 3x2 ?

The order of the solution matrix will be 2x2.

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Hello there! Thanks for reaching out to us at Careers360.

Ah, you're looking for CBSE quarterly question papers for mathematics, right? Those can be super helpful for exam prep.

Unfortunately, CBSE doesn't officially release quarterly papers - they mainly put out sample papers and previous years' board exam papers. But don't worry, there are still some good options to help you practice!

Have you checked out the CBSE sample papers on their official website? Those are usually pretty close to the actual exam format. You could also look into previous years' board exam papers - they're great for getting a feel for the types of questions that might come up.

If you're after more practice material, some textbook publishers release their own mock papers which can be useful too.

Let me know if you need any other tips for your math prep. Good luck with your studies!

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If you have uploaded screenshot of your 12th board result taken from CBSE official website,there won,t be a problem with that.If the screenshot that you have uploaded is clear and legible. It should display your name, roll number, marks obtained, and any other relevant details in a readable forma.ALSO, the screenshot clearly show it is from the official CBSE results portal.

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Hello Akash,

If you are looking for important questions of class 12th then I would like to suggest you to go with previous year questions of that particular board. You can go with last 5-10 years of PYQs so and after going through all the questions you will have a clear idea about the type and level of questions that are being asked and it will help you to boost your class 12th board preparation.

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A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is

Option 1)

0.34\; J

Option 2)

0.16\; J

Option 3)

1.00\; J

Option 4)

0.67\; J

A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times.  Assume that the potential energy lost each time he lowers the mass is dissipated.  How much fat will he use up considering the work done only when the weight is lifted up ?  Fat supplies 3.8×107 J of energy per kg which is converted to mechanical energy with a 20% efficiency rate.  Take g = 9.8 ms−2 :

Option 1)

2.45×10−3 kg

Option 2)

 6.45×10−3 kg

Option 3)

 9.89×10−3 kg

Option 4)

12.89×10−3 kg

 

An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

Option 1)

2,000 \; J - 5,000\; J

Option 2)

200 \, \, J - 500 \, \, J

Option 3)

2\times 10^{5}J-3\times 10^{5}J

Option 4)

20,000 \, \, J - 50,000 \, \, J

A particle is projected at 600   to the horizontal with a kinetic energy K. The kinetic energy at the highest point

Option 1)

K/2\,

Option 2)

\; K\;

Option 3)

zero\;

Option 4)

K/4

In the reaction,

2Al_{(s)}+6HCL_{(aq)}\rightarrow 2Al^{3+}\, _{(aq)}+6Cl^{-}\, _{(aq)}+3H_{2(g)}

Option 1)

11.2\, L\, H_{2(g)}  at STP  is produced for every mole HCL_{(aq)}  consumed

Option 2)

6L\, HCl_{(aq)}  is consumed for ever 3L\, H_{2(g)}      produced

Option 3)

33.6 L\, H_{2(g)} is produced regardless of temperature and pressure for every mole Al that reacts

Option 4)

67.2\, L\, H_{2(g)} at STP is produced for every mole Al that reacts .

How many moles of magnesium phosphate, Mg_{3}(PO_{4})_{2} will contain 0.25 mole of oxygen atoms?

Option 1)

0.02

Option 2)

3.125 × 10-2

Option 3)

1.25 × 10-2

Option 4)

2.5 × 10-2

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

Option 1)

decrease twice

Option 2)

increase two fold

Option 3)

remain unchanged

Option 4)

be a function of the molecular mass of the substance.

With increase of temperature, which of these changes?

Option 1)

Molality

Option 2)

Weight fraction of solute

Option 3)

Fraction of solute present in water

Option 4)

Mole fraction.

Number of atoms in 558.5 gram Fe (at. wt.of Fe = 55.85 g mol-1) is

Option 1)

twice that in 60 g carbon

Option 2)

6.023 × 1022

Option 3)

half that in 8 g He

Option 4)

558.5 × 6.023 × 1023

A pulley of radius 2 m is rotated about its axis by a force F = (20t - 5t2) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m2 , the number of rotations made by the pulley before its direction of motion if reversed, is

Option 1)

less than 3

Option 2)

more than 3 but less than 6

Option 3)

more than 6 but less than 9

Option 4)

more than 9

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