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
Evaluate exponential expression \( - {\text{ }}{{\text{2}}^{\text{5}}}.\)
  • A
    15
  • B
    16
  • C
    None of these
  • D
    -32
    Correct
2
Find the multiplicative inverse of\({\text{1}}{0^{--{\text{ 5}}}}\).
  • A
    \({\text{1}}{0^{\text{4}}}\)
  • B
    \({\text{1}}{0^{\text{5}}}\)
    Correct
  • C
    \({\text{1}}{0^{\text{3}}}\)
  • D
    \({\text{1}}{0^{\text{2}}}\)
3
Simplify and write in exponential form: \({p^{\text{3}}} \times {p^{--{\text{1}}0}}\)
  • A
    None of these
  • B
    \({p^{\text{7}}}\)
  • C
    \({p^{ - {\text{7}}}}\)
    Correct
  • D
    \({p^{ - {\text{5}}}}\)
4
Very small numbers can be expressed in standard form using __________ exponents.
  • A
    positive
  • B
    equal
  • C
    None of these
  • D
    negative
    Correct
5
\({a^0} = {\text{ }}\_\_\_\_\_\_\_\)
  • A
    1
    Correct
  • B
    3
  • C
    a
  • D
    2
6
The area of a square is given by the formula \({\text{A }} = {\text{ }}{{\text{c}}^{\text{2}}}\). What will be the total area of 5 such similar squares, if the side of a square is 8 ft?
  • A
    80 \({\text{f}}{{\text{t}}^{\text{2}}}\)
  • B
    None of these
  • C
    160 \({\text{f}}{{\text{t}}^{\text{2}}}\)
  • D
    320 \({\text{f}}{{\text{t}}^{\text{2}}}\)
    Correct
7
Evaluate the exponential expression \({\left( { - {\text{n}}} \right)^{\text{4}}} \times {\text{ }}{\left( { - {\text{n}}} \right)^{\text{2}}}\), for n = 5.
  • A
    3125
  • B
    15625
    Correct
  • C
    625
  • D
    25
8
Find the value of the expression \({\text{3 }} \times {\text{ }}{\left( { - {\text{m}}} \right)^{\text{2}}}\), for m = 4.
  • A
    48
    Correct
  • B
    24
  • C
    12
  • D
    36
9
Simplify: \({\left( {--{\text{ 4}}} \right)^{\text{5}}} \times {\text{ }}{\left( {-{\text{ 4}}} \right)^{-{\text{1}}0}}\)
  • A
    \(\frac{1}{{{{( - 4)}^5}}}\)
    Correct
  • B
    None of these
  • C
    \({{\text{4}}^{ - {\text{4}}}}\)
  • D
    \({{\text{4}}^{\text{5}}}\)
10
Simplify: \({{\text{2}}^{\text{5}}} \div {\text{ }}{{\text{2}}^{-{\text{ 6}}}}\)
  • A
    \({{\text{2}}^{{\text{11}}}}\)
    Correct
  • B
    None of these
  • C
    \({{\text{2}}^{{\text{1}}0}}\)
  • D
    \({{\text{2}}^{\text{9}}}\)
11
Simplify: \(\left\{ {{{\left( {\frac{1}{3}} \right)}^{ - 2}} - {{\left( {\frac{1}{2}} \right)}^{ - 3}}} \right\} \div {\left( {\frac{1}{4}} \right)^{ - 2}}\)
  • A
    None of these
  • B
    16
  • C
    \(\frac{1}{{16}}\)
    Correct
  • D
    8
12
Find the value of \({\left[ {{{\left( {\frac{{ - 2}}{3}} \right)}^{ - 2}}} \right]^1}\).
  • A
    \(\frac{5}{4}\)
  • B
    \(\frac{3}{4}\)
  • C
    \(\frac{9}{4}\)
    Correct
  • D
    \(\frac{7}{4}\)
13
Write the expression using exponents: \({\text{27 }} \times {\text{ 35 }} \times {\text{ 35 }} \times {\text{ 35}}\)
  • A
    \({\text{2}}{{\text{7}}^{\text{1}}} \times {\text{ 3}}{{\text{5}}^{\text{3}}}\)
    Correct
  • B
    \({\text{2}}{{\text{7}}^{\text{3}}} \times {\text{ 3}}{{\text{5}}^{\text{3}}}\)
  • C
    \({\text{2}}{{\text{7}}^{\text{3}}} \times {\text{ 3}}{{\text{5}}^{\text{1}}}\)
  • D
    \({\text{2}}{{\text{7}}^{\text{1}}} \times {\text{ 3}}{{\text{5}}^{\text{1}}}\)
14
Evaluate: - \({{\text{7}}^{\text{3}}}\)
  • A
    49
  • B
    -49
  • C
    -343
    Correct
  • D
    343
15
Find the multiplicative inverse of\({{\text{7}}^{--{\text{ 2}}}}\).
  • A
    \({{\text{7}}^{\text{3}}}\)
  • B
    \({{\text{7}}^{\text{5}}}\)
  • C
    \({{\text{7}}^{\text{2}}}\)
    Correct
  • D
    \({{\text{7}}^{\text{4}}}\)