Solar Cell

Q. 82. A 200W sodium Street lamp emits yellow light of wavelength 0.6 micrometer . Assuming it to be 25% efficient in converting electrical energy to light , the number of photons of yellow light it emits per second is

Q. The maximum amplitude for an amplitude modulated wave is found to be $12\text{V}$ while the minimum aplitude is found to be$3\text{V}$. The modulation index is $0.6x$ where $x$ is

Q. A photoelectric surface is illuminated successively by monochromatic light of wavelength $\lambda$. If the maximum kinetic energy of the emitted photoelectrons in the second case is $3$ times that in the first case, the work function of the surface of the material is ($h$ = Plancks constant, $c$ = speed of light)

1. $\frac{2hc}{\lambda }$
2. $\frac{hc}{3\lambda }$
3. $\frac{hc}{2\lambda }$
4. $\frac{hc}{\lambda }$

Q. If $L$ and $R$ are respectively inductance and resistance, then the dimensions of $\frac{L}{R}$ will be

1. $M^0{L}^0{T}^{-1}$
2. $M^{0}L{T}^0$
3. $M^0{L}^{0}T$
4. Cannot be represented in terms of $M,L$ and $T$

Q. Find out voltage applied to an electron microscope to produce electron of wavelength 0.6 angstrom- (1) 416.6 volt (2) 399.7 volt (3) 766.4 volt (4) 455.8 volt

Q. A beam of light consists of five wavelengths $4000\stackrel{\circ }{A},4800\stackrel{\circ }{A},6000\stackrel{\circ }{A},7000\stackrel{\circ }{A}and7800\stackrel{\circ }{A}$. The light beam is falling normally over a metal surface of area ${10}^{-4}{m}^2$ with a work function of 1.9 eV. Intensity of light beam is $7.5\times {10}^{-3}W/m^{-2}$, which is equally divided among the constituent wavelengths. If there is no loss of light energy, number of photoelectrons emitted per second is

1. $3.15\times {10}^{12}$
2. $1.12\times {10}^{12}$
3. $1.77\times {10}^{12}$
4. $4.06\times {10}^{12}$

Q. 49.ONE milliwatt of light of wavelength 4560 amstrong is incident on a cesium surface of work function 1.9 electronvolt.Given that quantum of efficiency of photoelectric emission is 0.5 percentage . The photoelectic current liberated as:

Q. A photo-cell is illuminated by a source of light placed at distance d from cell. Graph of photo current I vs. d is best represented by

1. 
2. 
3. 
4. 

Q.

The current density of a photo voltaic cell ranges from

1. $10-20\raisebox{1ex}{$mA$}\!\left/ \!\raisebox{-1ex}{$c{m}^2$}\right.$

2. $40-50\raisebox{1ex}{$mA$}\!\left/ \!\raisebox{-1ex}{$c{m}^2$}\right.$

3. $20-40\raisebox{1ex}{$mA$}\!\left/ \!\raisebox{-1ex}{$c{m}^2$}\right.$

4. $60-100\raisebox{1ex}{$mA$}\!\left/ \!\raisebox{-1ex}{$c{m}^2$}\right.$

Q.
Given figure shows amplitude modulated wave. By how much percentage is wave modulated?

1. 80%
2. 50%
3. 40%
4. 30%

Q.

What is the energy change known in photovoltaic cells?

Q. Which of the following graphs best represents the variation of photo current with respect to intensity of radiation?

1. 
2. 
3. 
4. 

Q. In a solar cell, current is generated due to bond breakage in

1. $n$ - region
2. $p$ - region
3. Depletion region
4. All of above

Q. Name any two elements that are used for making solar cell panels.

Q. Photovoltaic cells are used in
(i) static charge generator
(ii) printers
(iii) solar panels
(iv) xerox

1. (i), (ii)
2. (i), (iii)
3. (i), (ii), (iii)
4. all of these

Q. For an amplitude modulated wave , the maximum amplitude is found to be $10$ v while the minimum amplitude is found to be $2$v. Determine the modulation index $\mu$ .

Q. A photocell is illuminated by a small bright source placed $1m$ away. When the same source of light is placed $\frac{1}{2}m$ away, the number of electrons emitted by photo cathode would

1. decrease by a factor of $4$
2. increase by a factor of $4$
3. decrease by a factor of $2$
4. increase by a factor of $2$

Q. The maximum and minimum amplitude of an amplitude modulated wave is $16\text{V}$ and $8\text{V}$ respectively. The modulation index for this amplitude modulated wave is $x\times {10}^{-2}$. The value of $x$ is _____. $($up to two significant figures$)$

Q. Why GaAs is preferred over Si in a solar cell?

1. Because GaAs is easily available
2. Because GaAs has relatively higher absorption coefficient
3. Because GaAs has lower energy gap
4. Because GaAs is cheaper

Q. When light shines on a $p-n$ junction diode, the current $\left(I\right)vs$. voltage $\left(V\right)$ is observed as in the figure below:
In which quadrant(s) does the diode generate power, so that it can be used as a solar cell?

1. Quad $1$ and $3$ only
2. Quad $1$ only
3. Quad $4$ only
4. Quad $1$ and $4$ only

Q. Four harmonic waves of equal frequencies and equal intensities $I_0$ have phase angles $0,\frac{\pi }{3},\frac{2\pi }{3}and\pi$. When they are superposed, the intensity of the resulting wave is $n{I}_0$. The value of n is ___

Q. The V-I characteristic of a diode is shown in the figure. The ratio of forward to reverse bias resistance is :

1. $100$
2. ${10}^{-6}$
3. $10$
4. ${10}^6$

Q. The amplitude of wave disturbance propagating in the positive $x$-direction is given by $y=\frac{1}{(1+x{)}^2}$ at time $t=0$ and $y=\frac{1}{1+(x-2{)}^2}$ at $t=1\text{s}$, where $x$ and $y$ are in meter. The shape of wave does not change during the propagation. The velocity of the wave in $\left(\text{m/s}\right)$ will be _______.

Q.

THE CURRENT IN THE FORWARD BIAS IS KNOWN TO BE MORE THAN CURRENT IN REVERSE BIAS .WHAT IS THE REASON TO OPERATE THE PHOTODIODE IN REVERSE BIAS

Q. Which of the following can be used in the construction of solar material?

1. Sodium
2. Carbon
3. Silicon
4. Both A and C

Q. $I_{1}and{I}_2$ are the intensities of light falling on a solar cell. The I-V characteristics of the cell is $(I_2>I_1)$

1. 
2. 
3. 
4. 

Q. What is Solar Panel? Write its main three uses.

Q. In solar cells, a silicon solar cell $(\mu =3.5)$ is coated with a thin film of silicon monoxide $SiO(\mu =1.45)$ to minimise reflective losses from the surface. Determine the minimum thickness of $SiO$ that produces the least reflection at a wavelength of $550nm$, near the centre of the visible spectrum.

Q. Prepare an advertisement on the information given below.
Solar lamps - cheap cost - long lasting - maintenance free - good for hotels, homes, and offices - 50% offer for bulk order. [Intermediate]

Q. Which of the following material(s) is/are used in making a solar cell?

1. Silicon
2. Polycrystalline Thin Films
3. Gallium Arsenide
4. Both A and B