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
The value of \({{\text{2}}^{\text{3}}}\) is _____.
  • A
    4
  • B
    None of these
  • C
    8
    Correct
  • D
    2
2
The area of a square is given by the formula \({\text{A }} = {\text{ }}{{\text{c}}^{\text{2}}}\). What will be the total area of 5such similar squares, if the side of a square is 7 in?
  • A
    248 \({\text{i}}{{\text{n}}^{\text{2}}}\)
  • B
    242 \({\text{i}}{{\text{n}}^{\text{2}}}\)
  • C
    None of these
  • D
    245 \({\text{i}}{{\text{n}}^{\text{2}}}\)
    Correct
3
Evaluate exponential expression \({\left( { - {\text{m}}} \right)^{\text{2}}} \times {\text{ }}{\left( { - {\text{m}}} \right)^{\text{2}}}\), for m = 3.
  • A
    9
  • B
    27
  • C
    81
    Correct
  • D
    3
4
Find the value of x, if 32 =\({{\text{2}}^{\text{x}}}\).
  • A
    2
  • B
    3
  • C
    4
  • D
    5
    Correct
5
Simplify: \(\frac{{{3^{ - 5}} \times {{10}^{ - 5}} \times 125}}{{{5^{ - 7}} \times {6^{ - 5}}}}\)
  • A
    \({{\text{5}}^{\text{4}}}\)
  • B
    \({{\text{5}}^{\text{3}}}\)
  • C
    \({{\text{5}}^{\text{2}}}\)
  • D
    \({{\text{5}}^{\text{5}}}\)
    Correct
6
Find the value of m for which\({{\text{5}}^m} \div {\text{ }}{{\text{5}}^{--{\text{ 3}}}} = {\text{ }}{{\text{5}}^{\text{5}}}\).
  • A
    2
    Correct
  • B
    4
  • C
    None of these
  • D
    3
7
Find the value of x, if \({\text{625 }} = {\text{ }}{{\text{5}}^{\text{x}}}\).
  • A
    4
    Correct
  • B
    None of these
  • C
    3
  • D
    2
8
Evaluate\({{\text{8}}^{ - {\text{3}}}}\).
  • A
    \(\frac{1}{{216}}\)
  • B
    \(\frac{1}{{512}}\)
    Correct
  • C
    \(\frac{1}{{343}}\)
  • D
    \(\frac{1}{{125}}\)
9
Write the expression using exponents: \({\text{25 }} \times {\text{ 25 }} \times {\text{ 25}}\)
  • A
    \({\text{2}}{{\text{5}}^{\text{3}}}\)
    Correct
  • B
    \({\text{2}}{{\text{5}}^{\text{4}}}\)
  • C
    \({\text{2}}{{\text{5}}^{\text{5}}}\)
  • D
    \({\text{2}}{{\text{5}}^{\text{2}}}\)
10
Find the multiplicative inverse of\({\text{1}}{0^{--{\text{ 1}}00}}\).
  • A
    \({\text{1}}{0^{\text{5}}}\)
  • B
    \({\text{1}}{0^{{\text{2}}00}}\)
    Correct
  • C
    \({\text{1}}{0^{{\text{1}}0}}\)
  • D
    \({\text{1}}{0^{{\text{1}}00}}\)
11
Find the value of \(\left( {{{\text{3}}^0} + {\text{ }}{{\text{4}}^{--{\text{ 1}}}}} \right){\text{ }} \times {\text{ }}{{\text{2}}^{\text{2}}}\).
  • A
    5
    Correct
  • B
    2
  • C
    3
  • D
    4
12
Evaluate\({{\text{8}}^{\text{2}}}\).
  • A
    64
    Correct
  • B
    8
  • C
    24
  • D
    16
13
\({a^m} \times {a^n}\) = __________
  • A
    \({a^m}^{/n}\)
  • B
    \({a^m}^{ + n}\)
    Correct
  • C
    \({a^m}^n\)
  • D
    \({a^m}^{ - n}\)
14
\({\left( { - {\text{1}}} \right)^0}\)= ____
  • A
    2
  • B
    0
  • C
    1
    Correct
  • D
    -1
15
Express \({\text{7}}.{\text{54 }} \times {\text{ 1}}{0^{--{\text{ 4}}}}\) in usual form.
  • A
    0.000754
    Correct
  • B
    None of these
  • C
    0.00754
  • D
    0.0754