Explain how to calculate constant voltage source, Physics

Assignment Help:

Power is to be supplied from a source whose resistance is 20 K ? to a load of 100 ?. Would you consider it as a constant voltage source or current source? Explain.

Ans.

Given source is considered as a constant current source because, a source that has a very high internal resistance (20 K?) as compared to the load resistance (100 ?) is a constant current source.

Explanation: In figure below, a load impedance ZL is connected to a current source. Let It be the short-circuit current of source, and Zs be its internal impedance. Current IS is splitted into two parts IL through ZL and I1 through ZS. That is

 

1939_electronics.png

 

IS= I1+ IL

Or        I1= IS- IL

Because impedance Zs and  ZL are  in  parallel,  voltage  drop  across each must be equal, i.e.,

1145_equation.png

The above equation determines us that load current IL would remain almost the same as current IS, provided the ratio ZL/ZS= 100/20000 = 1/200 is small compared to unity. Source then behaves as a good current source.  Or we can say, the larger the value of internal impedance ZS (20K?) compared to load impedance ZL (100?), the smaller is the ratio ZL/ZS, and better it works as a constant current source.

 

 


Related Discussions:- Explain how to calculate constant voltage source

Define the unit of self inductance, Q. Define the unit of self inductance. ...

Q. Define the unit of self inductance. One henry is described as the self-inductance of a coil in which a change in current of one ampere per second produces an opposing emf of

Explain electric flux, Explain electric flux. Write its S.I. units. A spher...

Explain electric flux. Write its S.I. units. A spherical rubber balloon carries a charge that is uniformly distributed over its surface. As the balloon is blown up and enhances in

Light, diffenrence between pure and impure spectrum.

diffenrence between pure and impure spectrum.

Calculate the volumetric substrate utilization rate, Batch fermentation ...

Batch fermentation For aerobic cultivation of yeast the cell mass concentration, X t , and the concentration of the limiting substrate component (glucose), S t , has been deter

Phase difference between incident and reflected waves, What do you mean by ...

What do you mean by the phase difference between incident and reflected waves at a) an open end and b) closed end? What happens to the fundamental frequency of a stretched strin

What is a power, Q. What is a power? Answer: That seat of EMF" rep...

Q. What is a power? Answer: That seat of EMF" reply is SO wrong. Not merely is the rate of charge delivery not power but a seat of EMF doesn't deliver charge. A seat of EM

Does weight influence how far you jump, For the same leg strength / jumping...

For the same leg strength / jumping technique weight affects how far one can jump. Acceleration = Force / Mass With more mass you can't accelerate yourself as much when you j

What is intramodal dispersion in optical fibres, What is intramodal dispers...

What is intramodal dispersion in optical fibres? Intramodal dispersion (Δτ mat ) Intramodal dispersion is nothing although material dispersion. The velocity dissimilarity of

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd