Q2 of 805 Page 1

Plot a graph showing the variation of current ‘I’ versus resistance ‘R’, connected to a cell of emf E and internal resistance ‘r’.


In the figure, I = current flowing


E = emf of the cell


r = internal resistance


R = External resistance




From the equation, the current flowing through the cell connected to a load is inversely proportional to load, i.e. R.


Therefore the graph of I vs R will be exponentially decreasing.



More from this chapter

All 805 →
27

a) Draw the circuit diagram to determine the characteristics of a p- n-p transistor in common emitter configuration.

b) Explain, using I-V characteristics, how the collector current changes with the base current. How can (i) output resistance and (ii) current amplification factor be determined from the I-V characteristics?


OR


a) Why are photodiodes preferably operated under reverse bias when the current in the forward bias is known to be more than that in reverse bias?


b) The two optoelectronic devices: - Photodiode and solar cell, have the same working principle but differ in terms of their process of operation. Explain the difference between the two devices in terms of (i) biasing, (ii) junction area and (iii) I-V characteristics.

 1

In the given figure, charge + Q is placed at the centre of a dotted circle. Work done in taking another charge + q from A to B is W1 and from B to C is W2. Which one of the following is correct: W1 > W2, W1 = W2 and W1 < W2?

 3

State the factors on which the refractive index of a material medium for a given wavelength depends.

 4

Sketch the emergent wave front.