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WorksheetsIAT2 RES
Total questions: 50
Worksheet time: 50mins
Consider the following:
1) Solar Photovoltaic cell is an indirect energy conversion device.
2) A solar cell is basically an electrical current source, driven by a flux of radiation
Both options are true
Both options are false
First statement is true, second statement is false
First statement is false, second statement is true
Consider the following:
1) Solar Photovoltaic cell uses the sun's heat to generate electricity
2) Solar cell uses semiconductors.
Both options are true
Both options are false
First statement is true, second statement is false
First statement is false, second statement is true
Which of the following is not an advantage of solar PV system?
Availability
Can be located at remote location
Energy security
Easy installation and maintenance
Consider the following:
1) Solar Photovoltaic cell uses a PN junction.
2) Solar PV cell has an integral diode in its structure.
Both options are true
Both options are false
First statement is true, second statement is false
First statement is false, second statement is true
In a semiconductor in thermal equilibrium,
Drift current is greater than diffusion current
Drift current is lesser than diffusion current
Drift current is equal to diffusion current
No relation between drift and diffusion current
Drift of charge carriers is due to
Variation in charge concentrations
Presence of an electric field
doping concentration
None of the above
For a solar photovoltaic current to happen,
Band gap is more than the striking photon energy
Band gap is less than the striking photon energy
No relation between band gap and photon energy
Band gap has to beome zero.
Consider the following:
1) When an electron recombines with a hole, energy may be lost as heat or as a radiated photon.
2) Bandgap of semiconductors is in the visible range of electromagnetic spectrum.
Both statements are true
Both statements are false
First statement is true and second statement is false
First statement is false, second statement is true
In the model for PV cell, the series resistance indicates
Resistance of the semiconductor body
Resistance of the metal contact with semiconductor
Lead resistance
All of the above
Consider the following statements:
1) Fill factor lies between o to 1.
2) Fill factor should be close to zero.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
The open circuit voltage of a PV panel is 20V and the voltage at maximum power point is 15V. The short circuit current is 1A and the current at maximum power is 0.8A. The fill factor for the panel is
1.0
0.6
0.4
1.66
The maximum current generated by a solar cell does not depend on
Band gap of semiconductor
Optical absorption current of the material used in the cell
Thickness of the absorbing region
Load connected to the cell
The power generated by a solar cell is maximum in the
Knee region
Constant voltage region
Constant current region
None of the above
Consider the following statements:
1) When irradiance increases, short circuit current increases sizably.
2) When irradiance increases, open circuit voltage increases in the same proportion as short circuit current.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true.
In a PV panel, when temperature increases, short circuit current
Increases sizably
Increases slightly
Decreases slightly
Decreases sizably
In a PV panel, when temperature increases, open circuit voltage
Increases sizably
Increases slightly
Decreases slightly
Decreases sizably
Consider the following statements:
1) The maximum power generated by a PV panel increases with temperature
2) The maximum power generated by a PV panel increases with insolation.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
Solar cells are connected in series to
Boost up the terminal voltage
Increase the generated current
Achieve maximum power tracking
None of the above
Which factor has to be taken in to consideration in the mechanical layout of PV panels?
Clearance between panels
Angle of tilt
Shadowing between panels
All of the above
Which of the following is not used for making solar cells?
Gallium Arsenide
Lithium phosphate
Amorphous silicon
Cadmium Telluride
Which of the following solar cells has maximum efficiency
Monocrystalline SIlicon
Polycrystalline SIlicon
Amorphous silicon
Thin film
Partial shadowing in a PV panel
Reduces power output
Creates local hot spots
May even damage the panel
All of the above
Harmful effect due to partial shadowing can be overcome by
Connecting panels in series
Connecting panels in parallel
Putting a bypass diode in parallel with the cell groups
Putting a diode in series with the panel output
Which of the following is not a feature of Amorphous SIlicon PV cell?
No fixed crystal structure
Low cost
High efficiency
Incomplete covalent bonds
Consider the following regarding mono-crystalline PV cell:
1) Power and material consumption is low
2) Efficiency is higher
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
The schematic of the system shown refers to a
Stand-alone PV system with dc and ac loads
Grid-tied PV system with dc and ac loads
Grid-interactive PV system with dc and ac loads
None of the above
The largest solar PV park in the world is situated in
China
USA
India
Saudi Arabia
Which of these motors is generally not used for solar water pumping?
PMDC motors
Brush-less dc motors
Grid connected synchronous motors
Variable voltage and variable frequency ac motors with power electronic converters
Which of the following is not a disadvantage of a fractional short circuit MPPT algorithm?
Complex computation
Measuring short circuit current during system operation
Loss of power during measurement
Additional hardware requirement
Which of the following is not a disadvantage of a hill climbing MPPT algorithm?
Implementation difficulty
Oscillation of operating point around MPPT
Determining maximum power point during rapidly changing irradiances
Time required to reach maximum power point
In a PV system, it is required to vary the equivalent load resistance seen by the PV panel from 0 to infinity. Which of these converters would be suitable?
Buck converter
Boost converter
Buck-Boost converter
None of the above
An MPPT is basically a
ac-dc converter
dc-dc switching regulator
dc-ac inverter
amplifier
A grid interactive solar system:
always supplies power to the grid
supplies power to as well as receives power from the grid as required
always receives power from the grid
works only when the grid fails
If no load is connected to solar PV system:
it will stop absorbing light
it will dissipate energy in the panel and increase its temperature
its voltage will go on increasing till its breakdown
it will start reflecting the light
In a homogeneous pn junction:
the width of p and n layers are equal and constant throughout
the impurity levels on both sides of the junction are same
same semiconductor material is used on both sides of the junction
different semiconductor material on both sides of the junction but same level of doping
The photons having energy less than the energy gap
are absorbed and converted to heat
are not absorbed by the semiconductor material as it behaves as transparent to them
work jointly to produce electron-hole pair
are reflected from semiconductor material surface
What is responsible for movement of carriers after creation of an electron-hole pair due to radiation?
Diffusion process
Drift process
Built in electric field across the junction
External voltage
Cut-in velocity in a wind power machine is:
the maximum wind speed at which a wind turbine is designed to come into operation
the minimum wind speed at which a wind turbine is designed to come into operation
the wind speed at which the wind turbine stops functioning
the velocity of the rotor
The blade tip of a wind turbine is rotating at 2m /sec. The wind velocity is 10m /sec. What is the tip speed ratio?
0.2
0.5
1.0
None of the above
Consider the following statements:
a) Wind turbines produce flicker in the generated voltage when the blade comes in line with the tower.
b) PMSG connected to the grid generates harmonics which need to be filtered.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
Consider the following statements: The speed of a wind
turbine can be controlled by
a) Adjusting the electrical load.
b) Adjusting the pitch angle of the blades.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
Consider the following statements:
a) When a wind energy system generates more active power, the voltage at PCC tends to rise.
b) When a wind energy system consumes more
reactive power, the voltage at PCC tends to fall.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
Consider the following statements:
a) Grid connection of a wind energy system requires a stable grid.
b)Wind energy systems with Type C turbines tend to have a low power factor.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
A Type D, PMSG based wind turbine
a) Needs a capacitor bank at the stator terminals for reactive power supply.
b) Needs a soft starter for limiting inrush current.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
A grid-connected Type A wind energy system with a squirrel
cage induction generator,
a) Can supply active power.
b) Can supply reactive power.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
In a Type B wound rotor induction generator with an IGBT
based chopper,
a) When the duty cycle of chopper is 0, slip is minimum.
b) When the duty cycle of chopper is 1, slip is maximum
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
Consider the following statements: In a DFIG system,
a) Rotor side converter controls reactive power.
b) Grid side converter controls active power.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
Consider the following statements:
1) At cut-out speed, turbine is stopped and brakes are applied.
2) Between cut in speed and rated speed, the turbine tracks and operates at constant power.
Both statements are true
Both statements are false
First statement is true, second statement is false
First statement is false, second statement is true
At optimum tip speed ratio, the mechanical power
developed by the wind turbine is
Directly proportional to its angular velocity
Directly proportional to the square of its angular velocity
Directly proportional to the cube of its angular velocity
Inversely proportional to its angular velocity
A squirrel cage induction generator based wind turbine
operates at
Slip = 0
Slip =1
Slip < 0
Slip >1
