Telangana SCERT Solution Class VIII (8) Math Chapter 4 Exponents and Powers Exercise 4.2
(1) Express the following numbers in standard form.
(i) 0.000000000947
(ii) 543000000000
(iii) 48300000
(iv) 0.00009298
(v) 0.0000529
(2) Express the following numbers in usual form
(i) 4.37 × 105
(ii) 5.8 × 107
(iii) 32.5 × 10-4
(iv) 3.71529 × 107
(v) 3789 × 10-5
(vi) 24.36 × 10-3
(3) Express the following information in standard form
(i) Size of the bacteria is 0.0000004 m
(ii) The size of red blood cells is 0.000007mm
(iii) The speed of light is 300000000 m/sec
(iv) The distance between the moon and the earth is 384467000 m(app)
(v) The charge of an electron is 0.00000000000000000016 coulombs
(vi) Thickness of a piece of paper is 0.0016 cm
(vii) The diameter of a wire on a computer chip is 0.000005 cm
(4) In a pack, there are 5 books, each of thickness 20 mm and 5 paper sheets each of thickness 0.016mm. What is the total thickness of the pack.
(5) Rakesh solved some problems of exponents in the following way. Do you agree with the solutions? If not why? Justify your argument.
(i) x-3 × x-2 = x-6
(ii) x3/x2 = x4
(iii) x-2 = √x
(iv) 3x-1 = 1/3x