NCERT Solutions for Class 8 Maths Chapter 12 Exercise 12.2 Exponents and Powers

NCERT Solutions for Class 8 Maths Chapter 12 Exercise 12.2 Exponents and Powers, has been designed by the NCERT to test the knowledge. Class 8 maths chapter 12 exercise 12.2 contains 8 questions and each question has explained stepwise. If you are class 8th student you must be looking for the ncert solutions for class 8 maths chapter 12 exercise 12.2 for your exams preparation. Here we are providing complete NCERT class 8 maths chapter 12 exercise 12.2 solutions.

NCERT Solutions for Class 8 Maths Chapter 12 Exercise 12.2

• Use of Exponents to Express Small Numbers in Standard Form
• Comparing very large and very small numbers

NCERT Solutions for Class 8 Maths Chapter 12 Exercise 12.2 – Exponents and Powers

1. Express the following numbers in standard form.

i) 0000000000085
Sol.: – 0.0000000000085 = 8.5 × 10^-12

ii) 0.00000000000942
Sol.: – 0.00000000000942 = 9.42 × 10^-12

iii) 6020000000000000
Sol.: – 6020000000000000 = 6.02 × 10¹⁵

iv) 00000000837
Sol.: – 0.00000000837 = 8.37 × 10^-9

v) 31860000000
Sol.: – 31860000000 = 3.186 × 10¹⁰

2. Express the following numbers in usual form.

i. 3.02 × 10^-6
Sol.: – 3.02 × 10^-6 = 3.02 ×  = 0.00000302

ii. 4.5 × 10⁴
Sol.: – 4.5 × 10⁴ = 4.5 × 10000 = 45000

iii. 3 × 10^-8
Sol.: – 3 × 10^-8 = 3 ×  = 0.00000003

iv. 1.0001 × 10⁹
Sol.: – 1.0001 × 10⁹ = 1000100000

v. 5.8 × 10¹²
Sol.: – 5.8 × 10¹² = 5.8 × 1000000000000 = 5800000000000

vi. 3.61492 × 10⁶
Sol.: – 3.61492 × 10⁶ = 3.61492 × 1000000 = 3614920

3. Express the number appearing in the following statements in standard form.

i) 1 micron is equal to .
Sol.: – 1 micron = 1 × 10^-6 m

ii) Charge of an electron is 0.000,000,000,000,000,000,16 coulomb.
Sol.: – Charge of one electron = 1.6 × 10^-19 coulomb

iii) Size of a bacteria is 0.0000005 m
Sol.: – Size of a bacteria = 5 × 10^-7 m

iv) Size of a plant cell is 0.00001275 m
Sol.: – Size of a plant cell = 1.275 × 10^-5 m

v) Thickness of a thick paper is 0.07 mm
Sol.: – Thickness of a thick paper = 7 × 10^-2 mm

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

Sol.: – Thickness of the stack = Thickness of 5 book + Thickness of 5 Paper Sheet
= 5 × 20 + 5 × 0.016
= 100 + 0.08
= 100.08 mm
= 1.0008 × 10² mm

NCERT solutions for class 8 maths chapter 12 exercise 12.2

• Exercise 12.1 – Exponents and Powers
• Exercise 12.2 – Exponents and Powers

Download NCERT Solutions for Class 8 Maths Chapter 12 Exercise 12.2 Exponents and Powers