Power Play Class 8 MCQ Maths Chapter 2

Practicing Class 8 Maths MCQ and Class 8 Maths Chapter 2 Power Play MCQ Questions Online Test with Answers daily helps in time management.

MCQ on Power Play Class 8

Power Play MCQ Class 8

Class 8 Maths MCQ Chapter 2 Power Play

Multiple Choice Questions

Question 1.
The number 5^-2 can be written as
(a) 25
(b) \(\frac{1}{5^2}\)
(c) \(\frac{1}{5^{-2}}\)
(d) \(\frac{-2}{5}\)
Answer:
(b) \(\frac{1}{5^2}\)

Question 2.
The value of 2⁵ ÷ 2^-6 is
(a) 2⁵
(b) 2^-6
(c) 2^-11
(d) 2¹¹
Answer:
(d) 2¹¹

Question 3.
The standard form for 0.00000064 is
(a) 64 × 10⁸
(b) 6.4 × 10⁸
(c) 6.4 × 10^-8
(d) 6.4 × 10^-7
Answer:
(d) 6.4 × 10^-7

Question 4.
The usual form of 5.05 × 10^-5 is
(a) 0.505
(b) 0.0000505
(c) 5050000
(d) 0.000505
Answer:
(b) 0.0000505

Question 5.
The number by which (\(\frac{1}{2}\))^-3 should be divided so that the quotient may be equal to (60)^-1 is
(a) \(\frac{2}{9}\)
(b) 140
(c) \(\frac{-5}{8}\)
(d) 480
Answer:
(d) 480

Question 6.
Rajat created an informative message. He forwards the message to 5 people. Each of the five people forward the message to next 5 people and the chain goes on.
The message is forwarded 5 times. Which of the following calculation can be used to find number of people who have the informative message?
(a) 5⁰+5¹+5²+5³+5⁴
(b) 5¹+5¹+5¹+5¹+5¹
(c) 5⁰+5⁵+5¹⁰+5¹⁵+5²⁰
(d) 5⁵+5¹⁰+5¹⁵+5²⁰+5²⁵
Answer:
(a) 5⁰+5¹+5²+5³+5⁴

Assertion-Reason Based Questions

In the following questions (8-9), a statement of Assertion (A) is followed by a statement of Reason (R). Choose the correct option as:
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(c) Assertion is true but Reason is false.
(d) Assertion is false but Reason is true.

Question 1.
Assertion (A): a^m × b^m is equal to (ab)^m.
Reason (R): In multiplication of powers, multiply the bases if the exponent is same.
Answer:
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Question 2.
Assertion (A): 3.5 × 10⁷ is equal to 35000000.
Reason (R): An exponent refers to the number of times a number is multiplied by itself.
Answer:
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Fill in the blanks:

1. If 2^(3x+4) = 2^-x, then x = …….. .
Answer: -1

2. The value of (\(\frac{-1}{2}\)⁴= …….. .
Answer: \(\frac{1}{16}\)

3. The value of (\(\frac{1}{4}\)^-3 is …….. .
Answer: 64

4. The value of (\(\frac{1}{2^6}\)= …….. .
Answer: \(\frac{1}{64}\)

5. 1 km = …….. mm
Answer: 10⁶

Fun Activity

10. Across
2. 8 is the …….. of two exponents 1 and 7.
3. x^m is the …….. to x^-m.
5. The value of \(\frac{1}{3^{-2}}\) is ……..
6. If \(\frac{x^{\prime \prime}}{x^n}\) = x^p, then p is the …….. of m and n.
8. Very small numbers can be expressed in standard form using …….. exponents.
9. 0.0000125 is the ………. form of 1.25 × 10^-5.
Down
1. The value of reciprocal of 2^-10.
4. The value of xⁿ if n = 0 is ……..
7. 11⁷ is read as 11 raised to the …….. 7.

Answer:
Across
2. Sum
3. Reciprocal
5. Nine
6. Difference
8. Negative
9. Usual

Down
1. One thousand twenty-four
4. One
7. Power

Do as Directed

Question 1.
Find the multiplicative inverse of 3(7-1)⁰.
Answer: \(\frac{1}{3}\)

Question 2.
Simplify the ratio 8²: 4⁴.
Answer: 1:4

Question 3.
What is the value of (x^a+b)^(a-b) × (x^b+c)^(b-c) × (x^c+a)^(c-a) ?
Answer: 1

Question 4.
Find the value of a, if (x⁰ × x × x² × x³ × x⁴ × x⁵)^a = 1.
Answer: 0

Question 5.
Rewrite \(\frac{4^{-4}}{5^{-2}}\) using only the positive exponent.
Answer: \(\frac{5^2}{4^4}\)

Question 6.
Human body has approximately 100 billion cells. Write it in exponential form.
Answer: 10¹¹

Question 7.
Express the following measurements in standard form.
(a) Thickness of a paper is 0.05 mm.
Answer: 5 × 10^-2 mm

(b) Number of stars in a galaxy is 100 billion.
Answer: 10¹¹

(c) Distance from the Earth to the Moon is 384317695 m.
Answer: 3.84317695 × 10⁸

(d) Size of a plant cell is 0.00001275 m.
Answer: 1.275 × 10^-5

Question 8.
The mass of a proton is 1.67 × 10^-24g and that of an electron is 9.10 × 10^-28 g. What is the total mass?
Answer: 1.67091 × 10^-24 g

Question 9.
The diameters of the Sun and the Earth are 1.4 × 10⁹ m and 1.275 × 10⁷ m, respectively. Compare the two diameters.
Answer: 1.4 × 10⁹ m > 1.275 × 10⁷ m

Question 10.
Venus is the second planet from the sun. Our nearest neighbour ‘Venus’ is known as the Morning Star or Evening Star. Its distance from the Sun is about 108,200,000 km, and its radius is 6051.8 km . Venus is also called Earth’s sister or twin.
Based on the above information answer the following questions:
(a) Express the distance of Venus from the Sun in standard form.
Answer:
1.082 × 10⁸

(b) Express the radius of Venus in ‘metre’ in standard form.
Answer:
6.0518 × 10⁶c

(c) If a satellite launch vehicle on Venus has a speed of 20,000 km / h, then find the time it will take to reach the Sun from the Venus.
Answer:
5.41 × 10³ hours

(d) If the speed of light is 3 × 10⁵ km s, then how long will it take to reach on the surface of Venus from the Sun?
Answer:
3.6067 × 10² seconds