NCERT Solution for class 8 maths chapter 12 Exponents and Powers

NCERT solutions for class 8 maths chapter 12 Maths Exponents and Powers is prepared by academic team of Physics Wallah. we have prepared solutions for all exercise of chapter 12. Given below is step by step solutions of all questions given in NCERT textbook for chapter 12. Read chapter 12 theory make sure you have gone through the theory part of chapter 12 from NCERT textbook and you have learned the formula of the given chapter.Physics Wallah prepared a detail notes and additional questions for class 8 maths with short notes of all maths formula of class 8 maths. do read these contents before moving to solve the exercise of NCERT chapter 12. The NCERT solutions contains questions, answers, pictures and explanations for the complete Chapter 12 Exponents and Powers From of Science taught in Class 8.

NCERT Solutions for Class 8 Maths Exercise 12.1

Question 1.

Evaluate:

(i) Exponents and Powers/image001.png(ii) Exponents and Powers/image002.png (iii) Exponents and Powers/image003.png

Solution :

(i) Exponents and Powers/image001.png= 1/3²

Exponents and Powers/image005.png

= 1/9

(ii) Exponents and Powers/image007.png

Exponents and Powers/image005.png

= 1/16

(iii) Exponents and Powers/image003.png= Exponents and Powers/image009.png

Exponents and Powers/image005.png

= Exponents and Powers/image010.png= 32

Question 2.

Simplify and express the result in power notation with positive exponent:

(i) Exponents and Powers/image011.png

(ii) Exponents and Powers/image012.png

(iii) Exponents and Powers/image013.png

(iv) Exponents and Powers/image014.png

(v) Exponents and Powers/image014.png

Solution :

(i)Exponents and Powers/image016.png= Exponents and Powers/image017.pngExponents and Powers/image018.png

= Exponents and Powers/image019.pngExponents and Powers/image005.png

(ii) Exponents and Powers/image020.png

Exponents and Powers/image021.png

= Exponents and Powers/image022.pngExponents and Powers/image023.png

(iii) Exponents and Powers/image024.pngExponents and Powers/image021.png

= Exponents and Powers/image025.png

Exponents and Powers/image026.png

= Exponents and Powers/image027.pngExponents and Powers/image018.png

= Exponents and Powers/image028.pngExponents and Powers/image029.png

(iv) Exponents and Powers/image030.pngExponents and Powers/image018.png

= Exponents and Powers/image031.png= Exponents and Powers/image032.png= Exponents and Powers/image033.pngExponents and Powers/image034.png

= Exponents and Powers/image035.pngExponents and Powers/image005.png

 Exponents and Powers/image036.png

Question 3.

Find the value of:

Exponents and Powers/image039.png

Solution :

Exponents and Powers/image044.png

 Exponents and Powers/image048.png

Exponents and Powers/image058.png

Question 4.

Evaluate:

Exponents and Powers/image063.png

Solution :

 Exponents and Powers/image065.png

= 1/10 × 1/6 = 1/60

Question 5.
Find the value of m for which Exponents and Powers/image071.png

Solution :

Exponents and Powers/image071.png

Exponents and Powers/image073.pngExponents and Powers/image074.png

Exponents and Powers/image018.png

Exponents and Powers/image073.pngExponents and Powers/image074.png

Comparing exponents both sides, we get

Exponents and Powers/image073.png  m+3 = 5

Exponents and Powers/image073.png  m = 5 - 3

  Exponents and Powers/image073.png m = 2

Question 6.
Evaluate:

 Exponents and Powers/image079.png

Question 7.
Simplify:

 Exponents and Powers/image090.png

Exponents and Powers/image026.png

NCERT Solutions for Class 8 Maths Exercise 12.2

Question 1.

Express the following numbers in standard form:

(i) 0.0000000000085

(ii) 0.00000000000942

(iii) 6020000000000000

(iv) 0.00000000837

(v) 31860000000

Solution :

(i) 0.0000000000085

= 0.0000000000085 Exponents and Powers/image001.pngExponents and Powers/image002.png

= Exponents and Powers/image003.png

(ii) 0.00000000000942

= 0.00000000000942 Exponents and Powers/image001.pngExponents and Powers/image002.png

=Exponents and Powers/image004.png

(iii) 6020000000000000

= 6020000000000000 Exponents and Powers/image001.pngExponents and Powers/image005.png

= Exponents and Powers/image006.png

(iv) 0.00000000837

= 0.00000000837 Exponents and Powers/image001.pngExponents and Powers/image007.png

= Exponents and Powers/image008.png

(v) 31860000000 = 31860000000 Exponents and Powers/image001.pngExponents and Powers/image009.png= Exponents and Powers/image010.png

Question 2.

Express the following numbers in usual form :

 Exponents and Powers/image011.png

Solution :

Exponents and Powers/image017.png

Question 3.

Express the number appearing in the following statements in standard form :

(i)1 micron is equal to 1/ 1000000 m.

(ii) Charge of an electron is 0.000,000,000,000,000,000,16 coulomb.

(iii) Size of a bacteria is 0.0000005 m.

(iv) Size of a plant cell is

0.00001275 m.

(v) Thickness if a thick paper is 0.07 mm.

Solution :

(i) 1 micron

= Exponents and Powers/image021.pngm

(ii)Charge of an electron is

0.00000000000000000016 coulombs.

= 0.00000000000000000016 Exponents and Powers/image001.pngExponents and Powers/image022.png

= Exponents and Powers/image023.pngcoulomb

(iii) Size of bacteria = 0.0000005

= Exponents and Powers/image024.png= Exponents and Powers/image025.pngm

(iv) Size of a plant cell is 0.00001275 m

= 0.00001275 Exponents and Powers/image001.pngExponents and Powers/image026.png= Exponents and Powers/image027.pngm

(v) Thickness of a thick paper = 0.07 mm

= 7/100mm = Exponents and Powers/image029.pngmm

Question 4.

In a stack there are 5 books each of thickness 20 mm and 5 paper sheets each of thickness 0.016 mm. What is the total thickness of the stack?

Solution :

Thickness of one book = 20 mm

Thickness of 5 books = 20 × 5 = 100 mm

Thickness of one paper = 0.016 mm

Thickness of 5 papers = 0.016 × 5

= 0.08 mm

Total thickness of a stack = 100 + 0.08

=100.08 mm

= 100.08 Exponents and Powers/image001.pngExponents and Powers/image030.png

Exponents and Powers/image031.pngmm

Notes,worksheet and solved question for Maths class 8

  1. class 8 maths notes on chapter Liner equation in one variable
  2. class 8 maths notes on chapter algebric expression
  3. class 8 maths notes on chapter Mensuration
  4. class 8 maths notes on chapter Square and square roots
  5. class 8 maths notes on chapter statistice
  6. class 8 maths notes on chapter practical Geometry
  7. class 8 maths notes on chapter commericial maths
  8. class 8 maths notes on chapter solid shape
  9. class 8 maths notes on chapter quadrilaterals
  10. class 8 maths notes on chapter exponents
  11. class 8 maths notes on chapter factorisation
  12. class 8 maths notes on chapter inverse proporation
  13. class 8 maths notes on chapter cube and cube roots

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