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
Express \({\text{3 }} \times {\text{ 1}}{0^{--{\text{ 5}}}}\) in usual form.
  • A
    0.03
  • B
    0.00003
    Correct
  • C
    0.0003
  • D
    0.003
2
Evaluate the exponential expression \({{\text{d}}^{\text{4}}} \times {{\text{d}}^{\text{3}}}\), for d = 2.
  • A
    32
  • B
    16
  • C
    128
    Correct
  • D
    64
3
In a stack there are 5 books each of thickness 20mm and 5 paper sheets each of thickness 0.016 mm. What is the total thickness of the stack?
  • A
    \({\text{1}}.000{\text{8 }} \times {\text{ 1}}{0^{\text{4}}}\)
  • B
    \({\text{1}}.000{\text{8 }} \times {\text{ 1}}{0^{\text{3}}}\)
  • C
    \({\text{1}}.000{\text{8 }} \times {\text{ 1}}{0^{\text{2}}}\)
    Correct
  • D
    None of these
4
Express \({\text{3}}.0{\text{2 }} \times {\text{ 1}}{0^{--{\text{ 6}}}}\)in usual form:
  • A
    0.00000302
    Correct
  • B
    0.000302
  • C
    0.0000302
  • D
    None of these
5
Express \({\text{4}}.{\text{5 }} \times {\text{ 1}}{0^{\text{4}}}\) in usual form.
  • A
    45
  • B
    4500
  • C
    450
  • D
    45000
    Correct
6
Simplify: \(\frac{{25 \times {t^{ - 4}}}}{{{5^{ - 3}} \times 10 \times {t^{ - 8}}}}\)
  • A
    \(\frac{{625{t^4}}}{2}\)
    Correct
  • B
    625
  • C
    2
  • D
    \({{\text{t}}^{\text{2}}}\)
7
\({\left( { - {\text{3}}} \right)^{\text{5}}} \div {\text{ }}{\left( { - {\text{3}}} \right)^{\text{8}}} = {\text{ }}?\)
  • A
    \(\frac{1}{{27}}\)
  • B
    \( - \frac{1}{{27}}\)
    Correct
  • C
    \( - \frac{1}{2}\)
  • D
    \( - \frac{1}{5}\)
8
Write the expression using exponents: \({\text{21 }} \times {\text{ 21 }} \times {\text{ 21 }} \times {\text{ 21 }} \times {\text{ 21}}\)
  • A
    \({\text{2}}{{\text{1}}^{\text{4}}}\)
  • B
    \({\text{2}}{{\text{1}}^{\text{2}}}\)
  • C
    \({\text{2}}{{\text{1}}^{\text{5}}}\)
    Correct
  • D
    \({\text{2}}{{\text{1}}^{\text{3}}}\)
9
Write the expression using exponents: \({\text{52 }} \times {\text{ 52 }} \times {\text{ 52 }} \times {\text{ 52 }} \times {\text{ 52 }} \times {\text{ 52}}\)
  • A
    \({\text{5}}{{\text{2}}^{\text{6}}}\)
    Correct
  • B
    \({\text{5}}{{\text{2}}^{\text{3}}}\)
  • C
    \({\text{5}}{{\text{2}}^{\text{2}}}\)
  • D
    \({\text{5}}{{\text{2}}^{\text{4}}}\)
10
Write the expression using exponents: \({\text{35 }} \times {\text{ 35 }} \times {\text{ 35}}\)
  • A
    \({\text{3}}{{\text{5}}^{\text{5}}}\)
  • B
    \({\text{3}}{{\text{5}}^{\text{4}}}\)
  • C
    \({\text{3}}{{\text{5}}^{\text{3}}}\)
    Correct
  • D
    \({\text{3}}{{\text{5}}^{\text{2}}}\)
11
Evaluate: \({{\text{5}}^{\text{4}}}\)
  • A
    65
    Correct
  • B
    125
  • C
    25
  • D
    5
12
Evaluate: \({{\text{7}}^{\text{3}}}\)
  • A
    7
  • B
    343
    Correct
  • C
    1
  • D
    49
13
Evaluate: -\({{\text{9}}^{\text{2}}}\)
  • A
    9
  • B
    -81
    Correct
  • C
    81
  • D
    1
14
Evaluate: \({\text{2}}{{\text{1}}^0}\)
  • A
    21
  • B
    0
  • C
    441
  • D
    1
    Correct
15
Evaluate: \( - {{\text{9}}^{\text{3}}}\)
  • A
    729
  • B
    30
  • C
    -729
    Correct
  • D
    81