Tag: rules to write name and symbol for units of s.i. system

Questions Related to rules to write name and symbol for units of s.i. system

If units of mass and length are doubled and that of time remains same, in which quantity numberical value is unchanged?

  1. Force

  2. Energy

  3. Power

  4. Stress


Correct Option: D

When a symbol is used to represent a unit named after a person,  lower-case letters are used.

  1. True

  2. False


Correct Option: B
Explanation:
The given statement is false because upper-case letters are used to represent the symbol of a unit named after a person.
For example : Newton is denoted by  $N$

The correct way to represent an unit amount of force is :

  1. 1 newton

  2. 1 Newton

  3. 1 NEWTON

  4. None of these


Correct Option: A
Explanation:

The full name of the unit, irrespective of the fact whether it is named after a scientist or not, is always written with the lower initial letter. Hence 1 newton is correct way to write.

The correct way to represent ${10}^{9}W$ is

  1. $1GW$

  2. $1MW$

  3. $1TW$

  4. none of these


Correct Option: A
Explanation:

A unit may not be written with double prefixes. So, ${10}^{9}W$ may be written as $1GW$ and not as $1kMW$ and $1mTW$.

Which of the following is the right way of expressing 1 watt of power?

  1. 1 Watt

  2. 1 W

  3. 1 w

  4. 1 wt


Correct Option: B
Explanation:

The symbol for a unit, which is named after a scientist, is written with the first letter of the name as capital. So, 1 watt will be expressed as 1 W.

The symbol for a unit which is not named in the honour of some scientist is written in

  1. Lower initial letter

  2. Initial capital letter

  3. Lower letter

  4. All


Correct Option: C
Explanation:

The symbol for a unit which is not named in the honor of some scientist is written in lower letter.ex:- the symbol for metre is 'm',for kilo gram is 'kg' and for second is 's'.

The symbol for metre is written as :

  1. $m$

  2. $M$

  3. $\mu$

  4. All of the above 


Correct Option: A
Explanation:

The symbol for metre is 'm' ,for kilogram is 'kg' and for second is 's'.

Full name of the unit named in the honour of a scientist is written with

  1. Lower initial letter

  2. Initial capital letter

  3. Lower letter

  4. All


Correct Option: A
Explanation:

Full name of the unit named in the honour of a scientist is written with lower initial letter. For example, the full form for unit of force is newton and not Newton.

The ratio of SI unit to CGS unit of $g$ is :

  1. $10^2$

  2. $10$

  3. $10^{-1}$

  4. $10^{-2}$


Correct Option: A
Explanation:

SI unit of $g$ is   $m/s^2$
CGS unit of $g$ is  $cm/s^2$
We know that  $1 \ m = 100 cm$
Thus ratio of SI unit to CGS unit  $\dfrac{m/s^2}{cm/s^2} = \dfrac{100 \ cm/s^2}{cm/s^2} = 10^2$

SI unit of G is $Nm^2   kg^{-2}$. Which of the following can also be used as the SI unit of G?

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

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

  3. $m kg^{-3}s^{-1}$

  4. $m^2kg^{-3}s^{-2}$


Correct Option: A
Explanation:

$m^3kg^{-1}s^{2}$ is also used as the SI unit of G