Tag: matter around us

Questions Related to matter around us

$298 K$ is what temperature in Fahrenheit?

  1. $76.73F$

  2. $80F$

  3. $75F$

  4. $27F$


Correct Option: A
Explanation:

${ T } _{ K }={ (T } _{ F }+459.67)\times \frac { 5 }{ 9 } \ \Rightarrow 298={ (T } _{ F }+459.67)\times \frac { 5 }{ 9 } \ \Rightarrow \frac { 298\times 9 }{ 5 } -459.67={ T } _{ F }\ \Rightarrow { T } _{ F }=536.4-459.67={ 76.73 }^{ 0 }F$

The amount of heat energy released when a fuel burns completely is called calorific value.

  1. True

  2. False

  3. Nither

  4. Either


Correct Option: B
Explanation:
$\text{Calorific value= heat released per kg of fule}$

$\text{The amount of heat energy released when a one kilogram of fuel burns completely is called calorific value.}$

Which of the following is not a basic physical quantity?

  1. Length

  2. Force

  3. Time

  4. Amount of substance


Correct Option: B
Explanation:

The physical property of a body, substance or phenomenon that can be quantified by measurement is defined as a physical quantity.

There are seven fundamental physical quantities viz. time, length, mass, amount of substance, luminous intensity, temperature, and electric current.
Here force is a derived unit.
Thus the correct answer is force.

The commercial unit of electrical energy is :
  1. Watt

  2. Kilo Watt hour

  3. Watt/ hour

  4. Ohm


Correct Option: B
Explanation:

The kilowatt-hour is commonly used as a billing unit for energy delivered to consumers by electric utilities.

Energy spent in kilowatt-hour $=\cfrac {volt \times...........\times......}{1000}$.

  1. ampere, hour

  2. ohm,min

  3. ampere,min

  4. joule,hour


Correct Option: A
Explanation:

Energy = Work done $(in\ Watt) =  Power\times time = Voltage \times current \times time$


$Work\ done\ (in\ kilowatt) = \dfrac{(Voltage\times current\times time)}{ 1000}$

$Or\ work\ done\ (in\ kilowatt) = \dfrac{(Volt\times ampere\times hour)}{ 1000}$

Which of the following is wrong?

  1. 1 inch = 2.54 cm

  2. 1 foot = 3.305 m

  3. 1 mile = 1.609 km

  4. 1 lb. = 453.59 gm


Correct Option: B
Explanation:

Answer is option $B$. 

Since $1$ $foot=0.3048m$

Mark the conversion factor which is not correct.

  1. 1 atm $= 1.01325 \times 10^5 \ Pa$

  2. 1 metre $= 39.37\ inch$

  3. 1 litre $= 10^{-3}\ m^3$

  4. 1 inch $= 3.33\ cm$


Correct Option: D
Explanation:

A. 1 atm = $1.01325 \times 10^5\ Pa$

B. 1 metre = $39.37\ inches$
C. 1 litre = $10^{−3}\ m^3$
D. 1 inch = $2.54\ cm$
option D is correct

Atomic radius is expressed in the _______ units.

  1. angstrom

  2. cm

  3. m

  4. nm


Correct Option: A
Explanation:

Atomic radius is usually expressed in Angstrom units. It is because the size of atom is very small. It is equivalent to $1\times {10}^{-10}$metres.

Weight of diamonds are measured in________.

  1. aunce

  2. Kg

  3. carats

  4. pounds


Correct Option: C
Explanation:

One carat is equal to exactly $0.2$ grams.

The word 'carat' came from the "carob" seed, which was used by diamond traders as the original unit.

If $T _1$ and $T _2$ are two temperatures, which of the following expressions will yield the same value whether both temperatures are given in Celsius or Kelvin?

  1. $T _1+T _2$

  2. $T _1-T _2$

  3. $T _1\times T _2$

  4. $\dfrac{T _1}{T _2}$


Correct Option: B