Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

By rounding off,  (a) $20.96$ and (b) $0.0003125$ to three significant figures, we get 

  1. $21.0 ; \ 312 \times 10^{-4}$

  2. $21.0 ; \ 3.125 \times 10^{-4}$

  3. $2.10 ; \ 3.12 \times 10^{-4}$

  4. $210 ; \ 3.12 \times 10^{-4}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
By rounding off, 20.96 becomes 21.0 and 0.0003125 becomes $3.12\times 10^{-4} $


Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

The edge of a cube is a $=1.2\times 10^{-2}m$. Then its volume will be recorded as :

  1. $1.7\times 10^{-6} m^3$

  2. $1.70\times 10^{-6} m^3$

  3. $1.70\times 10^{-7} m^3$

  4. $1.78\times 10^{-6} m^3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Given that the edge of a cube is  $a=1.2 \times 10^{-2}m$.
The volume of a cube $= a^{3}$.
Volume $=[1.2 \times 10^{-2} ]^{3}$
The given volume of the cube is $1.728 \times 10^{-6}m^{3}$ 

$ \approx 1.7 \times 10^{-6}m^{3} \ \ \ (upto \ two \  significant  \ digits)$

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

Given $P = 0.0030 \,m, Q = 2.40 \,m$ and $R = 3000 m$, then number of significant figure in $P, Q, R$ are respectively:

  1. $1, 2, 1$

  2. $2, 3, 4$

  3. $4, 2, 1$

  4. $4, 2, 4$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$P = 0.00 \,\underset{1}{\underset{\uparrow}{3}}\underset{2}{\underset{\uparrow}{0}} m$

No. of digits (significant) $= 2$
$Q = \underset{1}{\underset{\uparrow}{2}}.\underset{2}{\underset{\uparrow}{4}}\underset{3}{\underset{\uparrow}{0}} \,m$
Digit $= 3$

$R = \underset{1}{\underset{\uparrow}{3}}\underset{2}{\underset{\uparrow}{0}}\underset{3}{\underset{\uparrow}{0}}\underset{4}{\underset{\uparrow}{0}} \,m$
Digit $= 4$

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

The number of significant figure in the result of (5.0m+6.0m) is

  1. Two

  2. Three

  3. Four

  4. One
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When adding or subtracting, the result should have the same number of decimal places as the measurement with the fewest decimal places. 5.0m and 6.0m both have one decimal place, so the sum 11.0m has three significant figures.

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

How many significant figures are there in 0.30100?

  1. 1

  2. 3

  3. 5

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

As per the following rules of significant numbers:
 1) ALL non-zero numbers (1,2,3,4,5,6,7,8,9) are ALWAYS significant.
2) ALL zeroes between non-zero numbers are ALWAYS significant.
3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant.
4) ALL zeroes which are to the left of a written decimal point and are in a number are ALWAYS significant.
Hence in given number i.e. 0.30100
According to the rule 1 and rule 3, the total significant numbers are 5. 

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

With due regards to significant figures $ 5.4 \times 0.125$ is equal to:

  1. 0.7

  2. 0.68

  3. 0.667

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Least number of significant figures before multiplication is $2$ in one of the multiplying numbers, then after the multiplication also, the answer should be in same number of significant digits.
$5.4\times 0.125=0.675=0.68$

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

How many significant figures are there in $0.030100\times 10^6$?

  1. 1

  2. 3

  3. 5

  4. 7
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

As per the following rules of significant numbers: 

1) ALL non-zero numbers (1,2,3,4,5,6,7,8,9) are ALWAYS significant. 
2) ALL zeroes between non-zero numbers are ALWAYS significant. 
3) Zeroes placed after other digits but behind a decimal point are significant 4)Zeroes placed before other digits are not significant.
Hence in given number i.e. $0.030100 \times 10^6$ can be further simplified as $30100.00$ 
According to the rule 1, 3 and rule 4, the total significant numbers are 5.