S Purkayastha Solutions for Chapter: Exponents and Powers, Exercise 4: Multiple Choice Questions

The value of ${\left(\frac{3}{4}\right)}^2\times {\left(\frac{3}{4}\right)}^{-4}$ is equal to 

The value of ${\left(-2\right)}^{-5}$ is equal to 

The value of ${\left(\frac{-1}{5}\right)}^4÷{\left(\frac{-1}{5}\right)}^8$ is equal to 

The mean distance of the moon from the earth is $384400000$ metres. Express the distance in scientific notation$?$

The distance of the earth from the sun is $149000000$ km. How long will a sunray take to reach the earth if it travels at a speed of $3.0\times {10}^{5 }\mathrm{km}/\mathrm{s} ?$

Express one second in a year in scientific notation.

The number of red blood cells per cubic mm of human body is approximately $5.5$ million. Express it in scientific notation.

The star sirius is about $8.1\times {10}^{13}$ km from earth. Assuming that light travels at a speed of $3.0\times {10}^5$ km per second, find how long will the light from sirius take to reach the earth.