Tag: physics

Questions Related to physics

What is the unit of latent heat ?

physics measurements and units summary of si units fundamental quantities system of units

  1. $J kg^{-1}$

  2. $J kg^{-1}mol^{-1}$

  3. $J mol^{-1}$

  4. $J$

Show answer
Correct Option: A
Explanation:

Latent heat is related to the heat energy as:
$Q=mL$
$\displaystyle L=\frac {Q}{m}=Jkg^{-1}$

Study the following

List - I List - II
a) Fundamental unit I) rad
b) Derived unit II) Kg-Wt
c) Practical unit III) N
d) Supplementary unit IV) Kg
physics measurements and units summary of si units fundamental quantities system of units

  1. a-I b-IV c-II d-III

  2. a-IV b-III c-II d-I

  3. a-I b-III c-IV d-I

  4. a-I b-II c-III d-IV

Show answer
Correct Option: B
Explanation:

Fundamental unit $\rightarrow$ $Kg$
Derived unit $\rightarrow$ $N$
Practical unit $\rightarrow$ $Kg-Wt$
Supplementary unit $\rightarrow$ $rad$

You can clearly see through a blue-tinted drinking glass.

physics light, shadows and images substances which allow light to pass through and those which do not transparent, opaque and translucent objects shadows

  1. True

  2. False

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Correct Option: B
Explanation:

Its a translucent object. light partially passes through it.

Wood is an example of opaque object.

physics light, shadows and images substances which allow light to pass through and those which do not transparent, opaque and translucent objects shadows

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

No light passes through opaque objects and we can't see through these objects.

For example, wood.

You can clearly see through opaque objects.

physics light, shadows and images substances which allow light to pass through and those which do not transparent, opaque and translucent objects shadows

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

It is false that you can clearly see through opaque objects as objects which are seen through are transparent and object which does not allow any light to pass through it are opaque.

Which of the following is transparent?

physics light and shadow substances which allow light to pass through and those which do not transparent, opaque and translucent objects shadows

  1. Stone

  2. Wood

  3. Plastic

  4. Glass

Show answer
Correct Option: D
Explanation:

A transparent object is one which allows all light to pass through it.
Since glass allows all the light to pass through it, so it is a transparent object.

Stone, wood and plastic are opaque materials.

Which of the following is an opaque object?

physics light and shadow substances which allow light to pass through and those which do not transparent, opaque and translucent objects shadows

  1. Wood

  2. Glass

  3. Air

  4. Vacuum

Show answer
Correct Option: A
Explanation:
Wood being an opaque object, does not allow light to pass through it.
All other objects allow light to pass through it.

Opaque objects:

physics light, shadows and images substances which allow light to pass through and those which do not transparent, opaque and translucent objects shadows

  1. Allow the light to pass through them

  2. Do not let the light to pass through them

  3. Absorb some amount of light and let the remaining to pass through them

  4. Allows the light from natural sources and rejects if it is from artificial sources

Show answer
Correct Option: B
Explanation:

The majority of objects are opaque, which means you can't see through them. This is due to the fact that light can't pass through them. Examples of opaque objects include wood, gold, cement, metal, some types of coloured plastic, and so on.

The minimum value of Compton wavelength shift is:

detection and recording of x-ray images option c: imaging physics

  1. $h/2 m _{0}c$

  2. $h/m _{0}c$

  3. $2h/m _{0}c$

  4. $zero$

Show answer
Correct Option: A
Explanation:

$\lambda -\lambda ^{1}  =  \dfrac{h}{m _e c}\ (1+cos  \theta )$

$\Delta \lambda ^{1}  =  \dfrac{h}{m _e c}\ (1+cos  \theta )$

$cf   \theta = 0^{0}$

then  $\Delta \lambda = 0$

Consider a metal used to produced some characteristic $X-$rays. Energy of $X-$ray are given by $E$ and wavelength as represented by $\lambda$. Then which of the following is true:

detection and recording of x-ray images option c: imaging physics

  1. $E(K _{\alpha}) > E({K} _{\beta}) > E(K _{\gamma})$

  2. $E(M _{\alpha}) > E(L _{\alpha}) > E(K _{\alpha})$

  3. $\lambda (K _{\alpha}) > \lambda (K _{\beta}) > \lambda (K _{\gamma})$

  4. $\lambda (M _{ \alpha })>\lambda (L _{ \alpha })>\lambda (K _{ \alpha })$

Show answer
Correct Option: B