Tag: matter around us

Questions Related to matter around us

SI unit for time is :

  1. minutes

  2. hours

  3. seconds

  4. days


Correct Option: C
Explanation:

SI unit of time is seconds.

Which of the following is not a conversion factor?

  1. 12 eggs = 1 dozen

  2. 30 lbs.

  3. 60 miles per hour

  4. 1 km/1,000 m

  5. 4 apples per week


Correct Option: C,D,E
Explanation:

Conversion factor involves same units. For example, length can be converted to length only, time to time only, etc.

Name and unit are listed, which is NOT correctly written?

  1. Torr and pressure

  2. Mass and grams

  3. Heat energy and kilopascals

  4. Volume and milliliter

  5. Temperature and Kelvin


Correct Option: C
Explanation:

Unit of Heat energy is joule ($J$) not kilopascals. kilopascal is unit for pressure.


Hence the correct option is C.

Convert $48.50mL$ to liters.

  1. $0.4850L$

  2. $4850L$

  3. $0.04850L$

  4. $0.00004850L$

  5. $4.850L$


Correct Option: C
Explanation:

We know that the 1 mL is equals to 0.001 L

hence $48.50$ mL is equals to $48.50$ multiplied by $0.001$ which comes $0.04850$ L.
Option C is correct answer.

Unit of J $pa^{-1}$ is equivalent to:

  1. $m^3$

  2. $cm^3$

  3. $dm^3$

  4. none of these


Correct Option: A
Explanation:

J/Pa =  Work/Pressure =  Nm/Nm-2 = m3

298 K is approximately what temperature in degrees Celsius?

  1. $25^oC$

  2. $24^oC$

  3. $29^oC$

  4. $27^oC$


Correct Option: A
Explanation:

Zero on the Celsius scale $(0^0C)$ is now defined as the equivalent to $273.15K$, with a temperature difference of $1^0C$ equivalent to a difference of $1K$, meaning the unit size in each scale is the same.

$T _k=T _c+273.15$
$T _k=$Temperature in kelvin.

$T _c=$Temperature in celsius.
$T _c=298-273=25^0C$.Option A is correct.

Prefix giga means:

  1. $10^{-9}$

  2. $10^{9}$

  3. $10^{6}$

  4. $10^{-6}$


Correct Option: B
Explanation:

The prefix of ${ 10 }^{ -9 }=$ nano

                      ${ 10 }^{ 9 }=$ giga
                      ${ 10 }^{ 6 }=$ mega
                      ${ 10 }^{ -6 }=$ micro
Therefore, $(B)$ is the correct answer.

The prefix of $10^{18}$ is:

  1. giga

  2. exa

  3. kilo

  4. nano

  5. mega


Correct Option: B
Explanation:

The prefix of ${ 10 }^{ 3 }=$ kilo

                       ${ 10 }^{ 6 }=$ mega
                       ${ 10 }^{ 9 }=$ giga
                       ${ 10 }^{ 18 }=$ exa
Therefore, the prefix of ${ 10 }^{ 18 }$ is exa

SI unit of energy is: 

  1. $kg\, m^2 s^{-2}$

  2. $kg\, m^{-1} s^{2}$

  3. $kg\, m^2 s^{-1}$

  4. $kg\, m^2 s^{2}$


Correct Option: A
Explanation:

The power required to do work by the application of force is energy.

Energy has same unit as that of work.
$\therefore$ S.I unit of Energy is $kgm^2 s^{-2}$

Which of the following is the correct unit for measuring nuclear radii?

  1. Micron

  2. Millimetre

  3. Angstrom

  4. Fermi


Correct Option: D
Explanation:

$\text{Nuclear radii are measured in Fermi ie. }$$10^{-15}$