Test: Power Play - 2 - Class 8 MCQ

In the expression 10²⁴, the number 10 is the base, and 24 is the exponent or power to which the base is raised. Therefore, the correct answer is 10.

The multiplicative inverse of 7^-2 is calculated by taking the reciprocal, which results in 7² = 49.

To solve (1/3)^-2, we use the rule that a^-b = (1/a)^b. Applying this, we get (1/3)^-2 = 3² = 9.

Solution:

The expression (3^-1 + 4^-1 + 5^-1)⁰ simplifies as follows:

• Any number raised to the power of 0 equals 1, as long as the base is not zero.
• In this case, the base is (3^-1 + 4^-1 + 5^-1), which is a valid number.
• Thus, the entire expression evaluates to 1.

count from rigth to left till you get last non-zero number 
like here 2 is the last non-zero number and for it we have to count 7 times
then write 2.16x 10⁷

Since the power is negative, we move 5 place to the left including 3.So answer is 0.00003

Each of the k items has n choices. Multiplying choices across all items gives n × n × ... (k times) = n^k

Given , The distance between the moon

and the earth is 384467000 m 

384467000

= 384467000 × ( 10⁸/10⁸ )

= ( 384467000/10⁸ ) × 10⁸

= 3.84467 × 10⁸ m

The expression 1¹⁵ involves raising 1 to the 15th power. Any number raised to any exponent remains unchanged if the base is 1. Therefore, 1¹⁵ = 1.

So it’s the multiplicative inverse of 1/125

Calculation:

- First, we need to solve the expression inside the parentheses: (3⁰ + 2⁰) x 5⁰
(3⁰ + 2⁰) x 5⁰    [ a⁰ = 1 ]
( 1 + 1) x 1
2 x 1 = 2

In the expression 8¹⁰⁰, the number 8 is the base, and 100 is the exponent. Therefore, the correct answer is 8.

The value of (2³)² is calculated as follows:

• First, calculate (2³):
  • 2³ = 2 × 2 × 2 = 8
• Next, square the result:
  • (8)² = 8 × 8 = 64

Thus, the final result is 64.

The solution for 1/5^-3 is as follows:

• We start with the expression 1/5^-3.
• Using the property of exponents, we know that 1/a^-n = aⁿ.
• Thus, 1/5^-3 = 5³.
• Calculating 5³ gives us 125.

The final answer is 125.

To express 140,000,000,000 kg in exponential form, we convert it to a number between 1 and 10 multiplied by a power of 10. Starting with 140,000,000,000, we move the decimal point two places to the left to get 1.4. Each place moved represents an exponent of 10. Moving the decimal two places gives us 10². Since there are nine additional zeros, we add 9 to the exponent, resulting in 10¹¹. Thus, 140,000,000,000 kg is written as 1.4 × 10¹¹ kg.

The expression (5^-1 + 7^-1 + 3^-1)⁰ simplifies to 1 because any non-zero number raised to the power of zero is 1.