Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics sources of energy wave energy tidal energy wave power and tidal power

Arrange the following steps of conversion of ocean thermal energy into electricity, in a proper sequence.
(a) The vapour of ammonia or CFC is passed over the turbines of generators.
(b) The hot water from the ocean is used to vapourise the liquid like ammonia or CFC.
(c) Cold water from the ocean depths is used to cool the vapour again into liquid.
(d) This cold liquid is again vapourised and the process continues.

  1. b a c d

  2. c a b d

  3. c b a d

  4. a b c d
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The hot water in the ocean is used to evaporate liquids like ammonia or CFC. This vapour is used to rotate the turbines of the generator and the vapour is again cooled down to a liquid by using the cold water from the ocean depth. This cooled liquid ammonia or CFC is again vapourised and the above process continues.

Multiple choice physics sources of energy wave energy tidal energy wave power and tidal power

Tidal energy is a major source of energy due to the presence of large water bodies on the earth.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

While tidal energy is a source of energy, it is not considered a 'major' source compared to other renewables due to limited suitable sites and high infrastructure costs.

Multiple choice physics sources of energy wave energy tidal energy wave power and tidal power

_________ are used to produce energy in OTEC.

  1. Tidal energy

  2. Temperature difference between the different layers of water in ocean

  3. Ocean waves

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

OTEC stands for Ocean Thermal Energy Conversion, which specifically uses the temperature gradient between surface and deep ocean layers to generate electricity.

Multiple choice physics sources of energy wave energy tidal energy wave power and tidal power

Which of the following is not a form of oceanic energy?

  1. Energy from biomass

  2. Tidal energy

  3. Ocean thermal energy

  4. Solar energy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Solar energy is a primary source of energy that drives other processes, but it is not classified as a form of oceanic energy itself, unlike tidal, wave, or thermal energy.

Multiple choice physics sources of energy wave energy tidal energy wave power and tidal power

The oceans cover almost ...... percent of the surface of earth with water and act as a vast collector of ...... energy.

  1. $71$, chemical

  2. $97$, solar

  3. $71$, solar

  4. $17$, hydroenergy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Oceans cover approximately 71 percent of the Earth's surface and act as a vast collector of solar energy, which is stored as heat in the surface waters.

Multiple choice limitations of bohr model and explanation of bohr's second postulate by matter waves bohr's model atoms atomic nuclei physics

In Bohr's atom the number of de Broglie's waves associated with an electron moving in $n^{th}$ permitted orbit is:-

  1. $n$

  2. $2n$

  3. $\dfrac{n}{2}$

  4. $n^2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
According to Bohr's postulate and de-Broglie the relation for $n^{th}$ orbit is like this $2\pi r _n=n\lambda$
Where $r _n$ is radius of $n^{th}$ orbit and $\lambda$ is deBroglie wavelength of electron in that orbit.
So number of de-Broglie wavelength is $n$.
Correct option is A.
Multiple choice limitations of bohr model and explanation of bohr's second postulate by matter waves bohr's model atoms atomic nuclei physics

Wavelength of first line in Lyman series is $\lambda $. The wavelength of first line in Balmer series is:

  1. $\dfrac { 5 }{ 27 } \lambda $

  2. $\dfrac { 32}{ 27 } \lambda $

  3. $\dfrac { 27 }{ 5 } \lambda $

  4. $\dfrac { 27 }{ 32 } \lambda $
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to Bohr, the wavelength emitted when an electron jumps from ${ n } _{ 1 }^{ th }$ to ${ n } _{ 2 }^{ th }$ orbit is
$E=\dfrac { hc }{ \lambda  } ={ E } _{ 2 }-{ E } _{ 1 }$
$\Rightarrow \dfrac { 1 }{ \lambda  } =R\left( \dfrac { 1 }{ { n } _{ 1 }^{ 2 } } -\dfrac { 1 }{ { n } _{ 2 }^{ 2 } }  \right) $
For first line in Lyman series
$\dfrac { 1 }{ { \lambda  } _{ L } } =R\left( \dfrac { 1 }{ { 1 }^{ 2 } } -\dfrac { 1 }{ { 2 }^{ 2 } }  \right) =\dfrac { 3R }{ 4 } $                        ......(i)
For first line in Balmer series,
$\dfrac { 1 }{ { \lambda  } _{ B } } =R\left( \dfrac { 1 }{ { 2 }^{ 2 } } -\dfrac { 1 }{ { 3 }^{ 2 } }  \right) =\dfrac { 5R }{ 36 } $                      ......(ii)
From equations (i) and (ii)
$\therefore \dfrac { { \lambda  } _{ B } }{ { \lambda  } _{ L } } =\dfrac { 3R }{ 4 } \times \dfrac { 36 }{ 5R } =\dfrac { 27 }{ 5 } $
$\therefore { \lambda  } _{ B }=\dfrac { 27 }{ 5 } \lambda $               $\left( \because { \lambda  } _{ L }=\lambda  \right) $