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Ncert Solutions for Exponents Class 8 CBSE Part 2



In this page we have NCERT book Solutions for Class 8th Maths:Exponents for EXERCISE 2 . Hope you like them and do not forget to like , social share and comment at the end of the page.

Question 1

Express the following numbers in standard form.

  1. 0.0000000000085
  2. 0.00000000000942
  3. 6020000000000000
  4. 0.00000000837
  5. 31860000000


Answer

  1. 0.0000000000085

    =8.5 ×10-12

     

  2. 0.00000000000942

    =9.42×10-12

     

  3. 6020000000000000

    =6.02×1015

     

  4. 0.00000000837

    =8.37 ×10-9

     

  5. 31860000000

    =3.186×1010

     

Question 2

Express the following numbers in usual form.

  1. 3.02 x 10-6
  2. 4.5 x 104
  3. 3 x 10-8
  4. 1.0001 x 109
  5. 5.8 x 1012
  6. 3.61492 x 106


Answer

  1. 3.02 x 10-6

    = .00000302

     

  2. 4.5 x 104

    =45000

     

  3. 3 x 10-8

    =.00000003

     

  4. 1.0001 x 109

    =1000100000

     

  5. 5.8 x 1012

    =5800000000000

     

       6. 3.61492 x 106

           =3614920

 

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 bacteria is 0.0000005 m

(iv)  Size of a plant cell is 0.00001275 m

(v) Thickness of a thick paper is 0.07 mm


Answer

  1. 1/1000000

=1×10-6

       2. 0.000, 000, 000, 000, 000, 000, 16

=1.6 ×10-19

     3. 0.0000005

=5 ×10-7

    4.  0.00001275

=1.275 ×10-5

   5.     0.07

=7×10-2

 

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?


Answer

Total thickness

=5×20  + 5X.016

=100  + 5× 1.6 ×10-2

=100  + .08

=100.08 mm

 

 


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