Tag: significant figures and rounding of digits

Questions Related to significant figures and rounding of digits

Write down the significant figures in the following
1. $5238$ N
2. $4200 $kg

  1. $4 , 4$

  2. $4 , 2$

  3. $4, 3$

  4. $5, 3$


Correct Option: B
Explanation:
All non-zero digits are significant and last zeros are not considered as significant.
(a) : The given number $5238$ has four significant figures.
(b) : The given number $4200$ has two significant figures.

if $L=2.331 cm$, $B = 2.1 cm$, then L+B=

  1. $4.431cm$

  2. $4.43cm$

  3. $4.5cm$

  4. $4.2cm$


Correct Option: A
Explanation:
Step 1
$L = 2.331 cm = 2.33$ (corrected to two decimal places) and $B = 2.1 cm$
Step 2
$L + B = 2.33 + 2.1 = 4.43cm. = 4.4cm$
(by the rule of addition the sum is expressed in minimum decimal places of terms in addition).

A packet contains silver powder of mass $20.23g\pm 0l01g$. Some of the powder of mass $5.75g\pm 0.01g$ is taken out from it. The mass of the powder left back is

  1. $14.48g\pm 0.00g$

  2. $14.48g\pm 0.02g$

  3. $14.5g\pm 0.1g$

  4. $14.5g\pm 0.2g$


Correct Option: B

All the numbers that can be formed using the digits, are arranged in the increasing order of magnitude. The rank of the number is (repetition not allowed).

  1. $58$

  2. $15$

  3. $50$

  4. $16$


Correct Option: A

The number of significant figures in 3400 is :

  1. 4

  2. 1

  3. 3

  4. 2


Correct Option: D
Explanation:

Trailing zeros in a whole number are not significant.Hence $3400$ has 2 significant digits only.

Therefore, option D is correct.

The distance $s$ traveled by a particle in time $t$ is
$s=ut-\cfrac{1}{2}g{t}^{2}$
The initial velocity of the particle was measured to be $u=1.11\pm 0.01m/s$ and the time interval of the experiment was $t=1.01\pm 0.1s$. The acceleration was taken to be $g=9.8\pm 0.1m/{s}^{2}$. With these measurements, the student estimates the total distance traveled. How should the student report the result?

  1. $1.121\pm 0.m$

  2. $1.1\pm 0.1m$

  3. $1.12\pm 0.07m$

  4. $1.1\pm 0.07m$


Correct Option: C

The diameter and height of a cylinder are measured by a meter scale to be $12.6\pm 0.1$ cm and $34.2\pm 0.1$ cm ,respectively. What will be the value of its volume in appropriate significant figures?

  1. $4264\pm 81{ cm }^{ 3 }$

  2. $4260\pm 80{ cm }^{ 3 }$

  3. $4264.4\pm 81.0{ cm }^{ 3 }$

  4. $4300\pm 80{ cm }^{ 3 }$


Correct Option: C