Tag: production of electricity from solar energy

Questions Related to production of electricity from solar energy

Which of the following is used in solar cooker to harvest the solar energy?

physics solar equipment production of electricity from solar energy solar power alternate sources of energy solar power plant solar energy and its applications renewable and non-renewable resources renewable and non-renewable sources of energy generation of electricity

  1. Solar panels

  2. Silicon cell

  3. Mirrors

  4. Glass lid

Show answer
Correct Option: B

In geothermal plants steam is raised by pumping water upto the layer of magma.                           .......................

physics energy : forms and sources production of electricity from solar energy solar equipment solar power renewable and non-renewable resources renewable and non-renewable sources of energy

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient

Show answer
Correct Option: A
Explanation:

The most common way of capturing the energy from geothermal sources is to tap into naturally occurring 'hydrothermal convection' systems, where cooler water seeps into Earth's crust, is heated up, and then rises to the surface. Once this heated water is forced to the surface, it is a relatively simple matter to capture that steam and use it to drive electric generators. Geothermal power plants drill their own holes into the rock to more effectively capture the steam.
Hence, the statement is true.

Relation between constant volume specific heat $(C _v)$ and degree of freedom $(f)$ for a gas is ($R$ is gas constant) 

physics solar equipment solar power plant production of electricity from solar energy solar power solar energy and its applications generation of electricity

  1. $C _v=\dfrac{f}{2} R$

  2. $C _v=fR$

  3. $C _v=\dfrac{f}{R}$

  4. $C _v=\dfrac{R}{f}$

Show answer
Correct Option: A
Explanation:

The internal energy of 1 mole of an ideal gas at temperature $T$ , having $f$ degrees of freedom is given by ,

          $U=N _{A}\times(1/2)fk _{B}T=(1/2)fRT$  ......................eq1
where $N _{A}=$Avogadro's number
           $k _{B}=$ Boltzmann's constant
from first law of thermodynamics ,
           $dU=dQ-dW$  ............eq2
At constant volume , $dV=0$ 
hence  $dW=PdV=0$
eq2 becomes , $dU=dQ$
but       $dQ=C _{V}dT$  (for 1 mole of gas)
therefore $dU=C _{V}dT$
or            $C _{V}=dU/dT$
putting the value of $U$ in this equation, we get
                $C _{V}=\frac{d(1/2)fRT}{dT}=\frac{f}{2}R$

Temperature of a gas is $20^o$C and pressure is changed from $1.01\times 10^5$ Pa to $1.165\times 10^5$ Pa. If volume is decreased isothermally by $10\%$. Bulk modulus of gas is?

physics solar equipment solar power plant production of electricity from solar energy solar power solar energy and its applications generation of electricity

  1. $1.55\times 10^5$

  2. $0.155\times 10^5$

  3. $1.4\times 10^5$

  4. $1.01\times 10^5$

Show answer
Correct Option: A
Explanation:
$B=-V\dfrac{\Delta P}{\Delta V}$
$=V _0\dfrac{(1.165-1.01)\times 10^5}{0.1\ V}$
$=1.55\times 10^5$

The room heater can maintain only ${16^0}C$ in the room when the temperature outside is -${20^0}C$. It is not warm and comfortable, that is why the electric stove with power of 1 kw is also plugged in.Together these two devices maintain the room temperature of ${22^0}C$. Determine the thermal  power of the heater.

physics solar equipment solar power plant production of electricity from solar energy solar power solar energy and its applications generation of electricity

  1. 3kW

  2. 4 kW

  3. 5kW

  4. 6kW

Show answer
Correct Option: C

The device which directly converts solar energy into electric energy is called

physics energy management solar power plant production of electricity from solar energy solar equipment solar energy and its applications

  1. solar cooker

  2. solar furnace

  3. solar cell

  4. none of these

Show answer
Correct Option: C
Explanation:

A solar cell takes solar energy directly from the sunlight and converts it into electrical energy.

In a mechanically isolated system, which interaction is allowed?

physics energy management solar power plant production of electricity from solar energy solar equipment solar energy and its applications

  1. Mass flow

  2. Work

  3. Heat flow

  4. None of these

Show answer
Correct Option: C
Explanation:

A mechanically isolated system is that , which cannot do work on environment and there is no exchange of mass between system and environment but exchange of heat is allowed between system and environment .

In a steady state process, which of the following quantity remains constant throughout the process

physics energy management solar power plant production of electricity from solar energy solar equipment solar energy and its applications

  1. Enthalpy

  2. Entropy

  3. Temperature and heat both

  4. Internal energy

Show answer
Correct Option: D
Explanation:

A steady state is a state which remains the same over given time period. In heat transfer problems if there is specific rate of heat transfer through medium (for conduction or convection) and if it remains constant at any time then it is said to have steady state heat transfer. In steady state, there may be different temperatures in body at different locations but the temperature at any given point will remain constant. If the temperature at all locations is same then it is uniform.

n a steady state process, Internal energy is quantity remains constant throughout the process

Which of the following is/are macroscopic variables:

physics energy management solar power plant production of electricity from solar energy solar equipment solar energy and its applications

  1. Volume

  2. Temperature

  3. Pressure

  4. All of the above

Show answer
Correct Option: D
Explanation:

Macroscopic variable is a measurable quantity used to describe the complete state of the system. The state of a macroscopic system in equilibrium can be described in terms of measurable properties as temperature, pressure, and volume, which are also known as thermodynamic variables.

Which of the following are macroscopic properties?

physics energy management solar power plant production of electricity from solar energy solar equipment solar energy and its applications

  1. texture

  2. phase

  3. viscosity

  4. all of the above

Show answer
Correct Option: D
Explanation:

$Answer:-$ D

Macroscopic properties are qualities that can be seen by the naked eye, and some are relative to the conditions under which a material or element is observed. The three most basic examples of macroscopic properties are color, shape and size.

Other examples of macroscopic properties include texture, phase (solid, liquid or gas), viscosity (if any) and density relative to surroundings (such as oil on water). The properties of an element or material tend to change, even if only slightly, as the conditions change. Examples of changing conditions include how metals tend to glow red when heated to extreme temperatures, how the viscosity of honey decreases with temperature or how the volume of $H _2O$ increases slightly when it freezes.