Secondary School (English Medium) (5 to 8) कक्षा ८ - CBSE Question Bank Solutions

An insect is on the 0 point of a number line, hopping towards 1. She covers half the distance from her current location to 1 with each hop. So, she will be at `1/2` after one hop, `3/4` after two hops, and so on.

Will the insect ever get to 1? Explain.

An electron’s mass is approximately 9.1093826 × 10^–31 kilograms. What is this mass in grams?

Consider a quantity of a radioactive substance. The fraction of this quantity that remains after t half-lives can be found by using the expression 3^–t. What fraction of substance remains after 7 half-lives? 

Use the properties of exponents to verify that statement is true.

`1/4 (2^n) = 2^(n - 2)`

Use the properties of exponents to verify that statement is true.

`4^(n - 1) = 1/4(4)^n`

Use the properties of exponents to verify that statement is true.

25(5^{n – 2}) = 5ⁿ

Fill in the blanks

In a repeater machine with 0 as an exponent, the base machine is applied 0 times. What do these machines do to a piece of chalk?

In a repeater machine with 0 as an exponent, the base machine is applied 0 times. What do you think the value of 6⁰ is?

What happens when 1 cm worms are sent through these hook-ups?

What happens when 1 cm worms are sent through these hook-ups?

Find a single machine that will do the same job as the given hook-up. 

a (× 2³) machine followed by (× 2^–2) machine.

Find a single machine that will do the same job as the given hook-up.

a (× 2⁴) machine followed by `(xx (1/2)^2)` machine.

Find a single machine that will do the same job as the given hook-up.

a (× 5⁹⁹) machine followed by a (5^–100) machine.

Find a single repeater machine that will do the same work as hook-up.

Find a single repeater machine that will do the same work as hook-up.

Find a single repeater machine that will do the same work as hook-up.

Find a single repeater machine that will do the same work as hook-up.

Find a single repeater machine that will do the same work as hook-up.

Find a single repeater machine that will do the same work as hook-up.