Tag: measurement of properties

Questions Related to measurement of properties

One gram of mass is equal to:

  1. $5\times { 10 }^{ 10 }erg$

  2. $9\times { 10 }^{ 20 }erg$

  3. $7\times { 10 }^{ 5 }erg$

  4. $11\times { 10 }^{ 12 }erg$


Correct Option: B
Explanation:

$E=mc^2$

$E=1\ g \times (3\times 10^{10}\ cm/s)^2 $
$=9\times 10^{20}\ erg$

Which of the following relationships are wrong?

  1. $1 \,atm\approx 0.1 \, bar$

  2. $1 \,liter= 1 \, dm^3$

  3. $1\, J =0.239 \, cal$

  4. $1\, eV =9.11 \times 10^{-4} J$


Correct Option: A,D
Explanation:

$1\quad atm=1.01325\quad bar\approx 1\quad bar\neq 0.1\quad bar$

$1\quad litre={ 10 }^{ -3 }{ m }^{ 3 }=1{ dm }^{ 3 }$
$1\quad cal =4.18\quad J \Rightarrow 1\quad J =0.239\quad cal\ 1\quad ev=1.6\times { 10 }^{ -19 }J \neq  9.11\times { 10 }^{ -4 }J$
Therefore, $(A). (D)$ are the correct answer.

Units of physical quantities can be expressed in terms of fundamental units and such units are called:

  1. Fundamental units

  2. Derived units

  3. Both a and b

  4. None of the above


Correct Option: B
Explanation:

Units of physical quantities can be expressed in terms of fundamental units and such units are called $\text{derived units}$. 

Unit of area can be an example for derived unit. If $L$ is the length of the square then $L \times L$ is $L^{2}$ is its area. Hence, option A is correct.

The units of fundamental physical quantities are called

  1. Fundamental units

  2. Derived units

  3. Both a and b

  4. None of the above


Correct Option: A
Explanation:

The units of fundamental physical quantities are called fundamental units. They are length, mass and time.
Hence option A is correct.

Match the following combinations of electrical units with their terms as single unit:

Electrical unit Single unit
(I) ampere-second A. coulomb
(II) volt-ampere B. ohm
(III) volt-ampere$^{-1}$ C. ampere
(IV) walt/ampere ohm D. watt
(V) joule / ampere second E. volt
  1. A- I B-III C-IV D-II E-V

  2. A- I B-II C-III D-IV E-V

  3. A- V B-IV C-III D-II E-I

  4. A- I B-V C-IV D-II E-III


Correct Option: A
Explanation:

Electrical unit     Single unit

(I) ampere-second                   coulomb

(II) volt-ampere                         Ampere

(III) volt-ampere$^{-1}$         Volt

(IV) walt/ampere ohm              Ohm

(V) joule / ampere second       Volt

So correct options are A- I B-III C-IV D-II E-V

Hence option A is correct.

Which of the following is the non- derived unit?

  1. Time

  2. Mass

  3. Length

  4. All of the above


Correct Option: D
Explanation:

Non-derived units or fundamental units are the units which are used to derive other units. The fundamental units are length, mass, temperature, time, electric current, liminous & mole.

Which of the following is not a basic physical quantity?

  1. Length

  2. Time

  3. Density

  4. Amount of substance


Correct Option: C
Explanation:

Basic physical quantities are those that are physical fundamental units. There are seven basic fundamental quantities: Length, mass, time, electric current, amount of substance, luminous intensity & temperature. The quantities which are derived with the help of these basic physical quantities are called derived quantities. They are density, volume, pressure, force, etc.

What should be the volume of the milk (in $m^3$) which measures 5 L?

  1. $5 \times 10^{-3} m^{3}$

  2. $5 \times 10^{3} m^{3}$

  3. $5 \times 1000 \ m^{3}$

  4. $5 \times 10^{6} m^{3}$


Correct Option: A
Explanation:
$1\ L=10^{-3}\ m^{3}$
Since 1 L = 1000 $cm^3$ and 1 m = 100 cm
$\dfrac {1 m}{100 cm} = 1 = \dfrac{100 cm}{1 m}, or (\dfrac {1 m}{100 cm})^3 = \dfrac{1m^3}{10^6cm^3}$ = $1^3$ = 1

Therefore $5\ L=5 \times 10^{-3}\ m^{3}$
option A is correct

The least count of burette used normally is $x$ (in mL). The value of $10x$ is:

  1. 1

  2. 1.5

  3. 0.10

  4. none of these


Correct Option: A
Explanation:

Normally least count of burette is $ 0.10 cm^3$.

So value of $10 x=10\times0.10=1$

How many seconds are there in 3 days?

  1. 259200 s

  2. 172800 s

  3. 24800 s

  4. 72000 s


Correct Option: A
Explanation:

$1\ min=60\ s$

$1 h = 60 min = 60 \times 60 s=3600\ s$
$1 day =24\ h=24 \times 3600\ s=86400\ s$
$3 days =3 \times 86400\ s=259200\ s$
option A is correct