Answered

A solar cell generates a potential difference of 0.10 V when a 400 Ω resistor is connected across it, and a potential difference of 0.15 V when a 1200 Ω resistor is substituted. (a) What is the internal resistance of the solar cell? Ω (b) What is the emf of the solar cell? V (c) The area of the cell is 4.0 cm2, and the rate per unit area at which it receives energy from light is 2.0 mW/cm2. What is the efficiency of the cell for converting the light energy to thermal energy in the 1200 Ω external resistor? %

Answer :

Manetho

Answer:

Solved

Explanation:

consider the emf of solar cell be ε and the output voltage be V . thus

      V = ε - i r

      = ε - ( V / R ) r

potential difference of 0.10 V when a 500 resistor is connected across the solar cell

   0.1 V =   ε - ( 0.1 V / 400Ω ) r .......(1)

   

potential difference of 0.15 V when a 1200 resistor is connected across the solar cell  

                 

                    0.15 V = ε - ( 0.15 V / 1200Ω ) r ..........(2)

   on solving equations (1) and (2)

   a)        internal resistance        r = 400 Ω

   b)        emf of the solar cell is ε =  0.2 V  

    c) received energy from light is   P received = 2.0 mW/cm^2  

                                                                     = (  2.0 mW/cm^2   ) ( 4 cm^2 )

                                                                      = 8 mW

efficiency of the cell for converting the light energy to thermal energy in the 1200 external resistor  

                     η   =   ( 0.15)^2 / 1200×8×10^-3 W    

                          = 0.234%

                         

The internal resistance, the emf of the solar cell, the efficiency  are mathematically given as

R=2.538*10^2

e=0.184V

n=0.127%

The internal resistance, the emf of the solar cell and the efficiency of the cell

a)

Generally the equation for the voltage is mathematically given as

V=e-iR

Therefore

V1=e(V1/V2)R

0.10=e-(0.10/300)R....1

0.15=e(0.15/1100)R....2

Therefore

R=2.538*10^2

b)

e=0.10+(0.10/300)R

e=0.184V

c)

efficiency n

n=(v^2/R)

[tex]n=\frac{(0.15^2/1100)*10^4}{8*10^-4*2*10^{-3}}[/tex]

n=1.278*10^{-3}

n=0.127%

For more information on Voltage

https://brainly.com/question/14883923

Other Questions