Questions · Page 5 of 5

M.C.Q. [1 Marks Each]

MCQ 2011 Mark
The value of $\Big(\frac{2}{5}\Big)^{-2}$ is:
  • A
    $\frac{4}{5}$
  • B
    $\frac{4}{25}$
  • $\frac{25}{4}$
  • D
    $\frac{5}{2}$
Answer
Correct option: C.
$\frac{25}{4}$
Using law of exponents, $\text{a}^{-\text{m}}=\frac{1}{\text{a}^\text{m}} [\because$ a is non$-$integer$]$
$\therefore \Big(\frac{2}{5}\Big)^{-2}=\frac{1}{\Big(\frac{2}{5}\Big)^{2}}$
$=\frac{1}{\frac{4}{25}}$
$=\frac{25}{4}$
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MCQ 2021 Mark
Mark $(\checkmark)$ against the correct answer of the following : $\Big(\frac{-6}{5}\Big)^{-1}=\ ?$
  • A
    $\frac{6}{5}$
  • B
    $\frac{-6}{5}$
  • C
    $\frac{5}{6}$
  • $\frac{-5}{6}$
Answer
Correct option: D.
$\frac{-5}{6}$
$\Big(\frac{-6}{5}\Big)^{-1}$
$=\Big(\frac{5}{-6}\Big)^{1}$
$=\frac{5}{-6}$
$=\frac{5\times-1}{-6\times-1}$
$=\frac{-5}{6}$
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MCQ 2031 Mark
$3^{-2} \times 3^{-5}$ is equal to:
  • A
    $3^{-3}$
  • B
    $3^{-10}$​​​​​​​
  • C
    $3^{7}$​​​​​​​
  • $3^{-7}$​​​​​​​
Answer
Correct option: D.
$3^{-7}$​​​​​​​
D. $3^{-7}$​​​​​​​
Solution:
$3^{-2} × 3^{-5} = \frac{1}{3^2}\times \frac{1}{3^5}$
$=\frac{1}{3^{2+5}}$
$=\frac{1}{3^7}$
$=3^{-7}$
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MCQ 2041 Mark
For any two non$-$zero rational nmbers a and b, $\text{a}^{4}\div\text{b}^4$ is equal to:
  • A
    $(\text{a}\times\text{b})^0$
  • B
    $(\text{a}\times\text{b})^{10}$
  • $(\text{a}\times\text{b})^5$
  • D
    $(\text{a}\times\text{b})^{25}$
Answer
Correct option: C.
$(\text{a}\times\text{b})^5$
$\text{a}^{\text{n}}\times\text{b} ^{\text{n}}=(\text{a}\times{\text{b}} )^\text{n}$
Hence,
$\text{a}^\text{5}\times\text{b}^5=(\text{a}\times\text{b} )^5$
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MCQ 2051 Mark
The value of $\log^{\text{x}^{2}\text{yz}}_\text{xyz}+\log^{\text{xy}^{2}\text{z}}_\text{xyz}+\log^{\text{xyz}^{2}}_\text{xyz}$ is equal to:
  • A
    $2$
  • B
    $1$
  • $4$
  • D
    Not
Answer
Correct option: C.
$4$
$4$
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MCQ 2061 Mark
$a^m \times b^m$ is equal to:
  • $(ab)^m$
  • B
    $(ab)^{-m}$
  • C
    $a^mb$
  • D
    $ab^m$
Answer
Correct option: A.
$(ab)^m$
A.  $(ab)^m$
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MCQ 2071 Mark
In standard form $56700000$ is written as ______.
  • $5.67 \times 10^7$
  • B
    $567 \times 10^7$
  • C
    $5.67 \times 10^5$
  • D
    $567 \times 100000$
Answer
Correct option: A.
$5.67 \times 10^7$
A.  $5.67 \times 10^7$
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MCQ 2081 Mark
The value of $2^{-2}$ is:
  • A
    $4$
  • B
    $\frac{1}{2}$
  • C
    $2$
  • $\frac{1}{4}$
Answer
Correct option: D.
$\frac{1}{4}$
D.  $\frac{1}{4}$
Solution:
$2^{-2} = \frac{1}{2^2} = \frac{1}{4}$
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MCQ 2101 Mark
Expand $1256.249$ using exponents.
  • $1 \times 10^3+2 \times 10^2+5 \times 10^1+6 \times 10^0$$+2 \times 10^{-1}+4 \times 10^{-2}+9 \times 10^{-3} $
  • B
    $1 \times 10^5+2 \times 10^2+5 \times 10^1+6 \times 10^0$$+2 \times 10^{-1}+4 \times 10^{-2}+9 \times 10^{-3} $
  • C
    $1 \times 10^4+2 \times 10^2+5 \times 10^2+6 \times 10^1$$+2 \times 10^3+4 \times 10^{-1}+9 \times 10^{-2}$
  • D
    None of these.
Answer
Correct option: A.
$1 \times 10^3+2 \times 10^2+5 \times 10^1+6 \times 10^0$$+2 \times 10^{-1}+4 \times 10^{-2}+9 \times 10^{-3} $
A.  $1 \times 10^3+2 \times 10^2+5 \times 10^1+6 \times 10^0$$+2 \times 10^{-1}+4 \times 10^{-2}+9 \times 10^{-3} $
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MCQ 2111 Mark
$\frac{5^7}{6^7}$ will give the value:
  • $(\frac{5}{6})^7$
  • B
    $(\frac{5}{6})^0$
  • C
    $(\frac{5}{6})^{-7}$
  • D
    $(\frac{6}{5})^{-7}$
Answer
Correct option: A.
$(\frac{5}{6})^7$
By exponent law,
$\frac{\text{a}^\text{m}}{\text{b}^\text{m}}= \big(\frac{\text{a}}{\text{b}}\big)^\text{m}$
$\frac{5^7}{6^7} = \big(\frac{5}{7}\big)^7$
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MCQ 2121 Mark
$(2^\circ + 4^{-1}) \times 2^2$is equal to.
  • A
    $2$
  • B
    $3$
  • C
    $4$
  • $5$
Answer
Correct option: D.
$5$
D.  $5$
Solution:
$(2^\circ+4^{-1})\times2^2$
$=\big(1+\frac{1}{4}\big)\times4$
$=\frac{5}{4}\times4 = 5$
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MCQ 2131 Mark
If y be any non-zero integer, then $y^0$ is equal to:
  • $1$
  • B
    $0$
  • C
    $-1$
  • D
    Not defined
Answer
Correct option: A.
$1$
A.  $1$
Solution:
Using law of exponents,
$a^0 = 1$ [$\because$ a is non-zero integer]
Similarly,
$y^0 = 1$
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MCQ 2141 Mark
The multiplicative inverse of $10^{10}$ is:
  • A
    $10$
  • B
    $\frac{1}{10}$
  • C
    $10^{-10}$
  • $10^{10}$
Answer
Correct option: D.
$10^{10}$
D.  $10^{10}$
Solution:
$10^{-10}\times10^{10} = 10^{-10+10} = 10^\circ= 1$
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MCQ 2151 Mark
$\Big(\frac{3}{4}\Big)^{5}\div\Big(\frac{5}{3}\Big)^{5}$ is equal to:
  • $\Big(\frac{3}{4}\div\frac{5}{3}\Big)^5$
  • B
    $\Big(\frac{3}{4}\div\frac{5}{3}\Big)^1$
  • C
    $\Big(\frac{3}{4}\div\frac{5}{3}\Big)^0 $
  • D
    $\Big(\frac{3}{4}\div\frac{5}{3}\Big)^{10} $
Answer
Correct option: A.
$\Big(\frac{3}{4}\div\frac{5}{3}\Big)^5$
We have:
$\Big(\frac{3}{4}\Big)^{5}\div\Big(\frac{5}{3}\Big)^{5}$
$=\Big( \frac{3}{4}\div\frac{5}{3}\Big)^5$
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M.C.Q. [1 Marks Each] - Page 5 - MATHS STD 8 Questions - Vidyadip