Tag: measurement of properties

Questions Related to measurement of properties

In which of the following numbers, all zeros are significant?

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. 5.0005

  2. 0.0030

  3. 30.000

  4. 0.5200

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Correct Option: A
Explanation:

Any zeros between two significant digits are significant.

Non zero digits are always Significant.

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. True

  2. False

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Correct Option: A
Explanation:

Non zero digits are always significant it is a true statement.

Ex: $1234$ Total significant numbers are 4.

Calculate the following with due regard for significant figures:


 $\dfrac{1.53\times 0.9995}{1.592}$.

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. $0.961$

  2. $0.921$

  3. $0.123$

  4. $0.913$

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Correct Option: A
Explanation:

$1.53\times 0.9995=1.529=1.53$ .....By applying significant figure rule


$\cfrac { 1.53\times 0.9995 }{ 1.592 } =\cfrac { 1.53 }{ 1.592 } =0.961$

Hence, the correct option is $A$

If repeated measurements give values close to one another, the number is:

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. surely precise

  2. surely accurate

  3. surely precise and accurate

  4. all of these are correct

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Correct Option: A
Explanation:

Precision $=$ Individual value $-$ mean value

If the repeated measurement value is close to one another, the mean value will be close to the individual values. Therefore, their difference i.e. Precision is close to zero. Therefore, they are surely precise.
But the accuracy is the difference between the actual value & the mean value.
As we do not know the actual value, we cannot predict its accuracy.

The number of significant figures present in $4.50 \times 10^{3} $ is:

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. 2

  2. 3

  3. 4

  4. 5

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Correct Option: A
Explanation:
Number of significant figures present in $4.50 \times {10}^{3}$-
$4.50 \times {10}^{3} = 4500$
Thus, there are two significant figures.

The number of significant figures in 0.02300 is ?

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. 6

  2. 2

  3. 4

  4. 3

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Correct Option: C

significant number in 0.002930

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. 6

  2. 5

  3. 4

  4. 3

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Correct Option: C

Which of the following values possess maximum number of significent zeros?

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. $0.00007$

  2. $0.00070$

  3. $20.000$

  4. $0.800$

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Correct Option: C

After rounding off 1.235 and 1.225, we will have their answers respectively as 

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. 1.23, 1.22

  2. 1.24 , 1.23

  3. 1.23 , 1.23

  4. 1.24 , 1.22

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Correct Option: D

Which among the following measurements contains the highest number of significant figures? 

chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

  1. $1.123 \times 10^{-3}kg$

  2. $1.2 \times 10^{-3}kg$

  3. $0.123 \times 10^{3}kg$

  4. $2 \times 10^{5}kg$

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Correct Option: A