Class 8 Exponents And Powers CBSE Questions & Answers

Class 8 · Exponents And Powers

This is Mathematics Class 8 Exponents and Powers CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Simplify and write in exponential form: \({{\text{3}}^{\text{2}}} \times {\text{ }}{{\text{3}}^{-{\text{5}}}} \times {\text{ }}{{\text{3}}^{\text{6}}}\)
  • A
    \({{\text{3}}^{\text{4}}}\)
  • B
    \({{\text{3}}^{\text{5}}}\)
  • C
    \({{\text{3}}^{\text{3}}}\)
    Correct
  • D
    \({{\text{3}}^{ - {\text{3}}}}\)
2
\({\left( {{a^m}} \right)^n}\) = __________
  • A
    \({a^{m - n}}\)
  • B
    \({a^{m/n}}\)
  • C
    \({a^{mn}}\)
    Correct
  • D
    \({a^{m + n}}\)
3
\({a^{--m}}\) is the multiplicative inverse of _________.
  • A
    \({a^{2m}}\)
  • B
    None of these
  • C
    \({a^{ - m}}\)
  • D
    \({a^m}\)
    Correct
4
A group of students were given an assignment to collect different types of leaves. The group collected 243 types of leaves. Represent the number of leaves collected in the form of exponential expression with its base being indivisible.
  • A
    \({{\text{3}}^{\text{5}}}\)
    Correct
  • B
    \({{\text{3}}^{\text{4}}}\)
  • C
    \({{\text{3}}^{\text{2}}}\)
  • D
    \({{\text{3}}^{\text{3}}}\)
5
Find the value of the expression \({\left( {{\text{2a}}} \right)^{\text{2}}}\), for a = 8.
  • A
    64
  • B
    32
  • C
    128
  • D
    256
    Correct
6
Write the correct base and exponent for the given expression. 625 =\({\left( ? \right)^{\text{2}}}\) = 5(?)
  • A
    5 and 4
  • B
    25 and 4
    Correct
  • C
    25 and 3
  • D
    None of these
7
Simplify and write the answer in the exponential form: \(\frac{1}{8} \times {\left( 3 \right)^{ - 3}}\)
  • A
    \(\frac{1}{{{6^3}}}\)
    Correct
  • B
    \({{\text{6}}^{ - {\text{2}}}}\)
  • C
    None of these
  • D
    \({{\text{6}}^{\text{3}}}\)
8
Simplify and write the answer in the exponential form: \({\left( { - 3} \right)^4} \times {\left( {\frac{5}{3}} \right)^4}\)
  • A
    \({{\text{5}}^{\text{3}}}\)
  • B
    \({{\text{5}}^{\text{4}}}\)
    Correct
  • C
    \({{\text{5}}^{\text{2}}}\)
  • D
    \({{\text{5}}^{ - {\text{4}}}}\)
9
Simplify: \({\left( {\frac{5}{8}} \right)^{ - 7}} \times {\left( {\frac{8}{5}} \right)^{ - 5}}\)
  • A
    64
  • B
    25
  • C
    \(\frac{{64}}{{25}}\)
    Correct
  • D
    \(\frac{{25}}{{64}}\)
10
Evaluate\({{\text{6}}^{ - {\text{2}}}}\).
  • A
    \(\frac{1}{{25}}\)
  • B
    \(\frac{1}{{36}}\)
    Correct
  • C
    \(\frac{1}{{16}}\)
  • D
    \(\frac{1}{4}\)
11
Write the expression using exponents. \({\text{3 }} \times {\text{ 3 }} \times {\text{ 35 }} \times {\text{ 35}}\)
  • A
    \({{\text{3}}^{\text{2}}} \times {\text{ 3}}{{\text{5}}^{\text{2}}}\)
    Correct
  • B
    \({{\text{3}}^{\text{3}}} \times {\text{ 3}}{{\text{5}}^{\text{2}}}\)
  • C
    \({{\text{3}}^{\text{3}}} \times {\text{ 3}}{{\text{5}}^{\text{3}}}\)
  • D
    \({{\text{3}}^{\text{2}}} \times {\text{ 3}}{{\text{5}}^{\text{3}}}\)
12
Evaluate the exponential expression \({\text{6 }} \times {\text{ 1}}{0^{\text{5}}}\).
  • A
    60000
    Correct
  • B
    6000
  • C
    600
  • D
    60
13
Find the multiplicative inverse of\({{\text{5}}^{-{\text{ 3}}}}\).
  • A
    \({{\text{5}}^{\text{6}}}\)
  • B
    \({{\text{5}}^{\text{4}}}\)
  • C
    \({{\text{5}}^{\text{3}}}\)
    Correct
  • D
    \({{\text{5}}^{\text{5}}}\)
14
Find the value of\(\left( {{{\text{3}}^{--{\text{ 1}}}} + {\text{ }}{{\text{4}}^{-{\text{ 1}}}} + {\text{ }}{{\text{5}}^{-{\text{ 1}}}}} \right)\).
  • A
    2
  • B
    1
    Correct
  • C
    4
  • D
    3
15
\({a^m} \times {b^m} = {\text{ }}\_\_\_\_\_\_\_\)
  • A
    \({\left( {ab} \right)^m}\)
    Correct
  • B
    \({\left( b \right)^m}\)
  • C
    None of these
  • D
    \({\left( a \right)^m}\)