Q24 of 71 Page 418

Each of the resistances shown in figure has a value of 20 Ω. Find the equivalent resistance between A and B. Does it depend on whether the point A or B is at higher potential?



The given figure can also be made as:

which looks like a Wheatstone bridge. Hence, current through the middle arm = 0A


∴ Current through the diode = 0A.


Equivalent circuit diagram becomes:


Untitled.png


∴ Net resistance


• R =


• R = 20ohm


More from this chapter

All 71 →
22

Consider a p-n junction diode having the characteristic i= i0(eeV/kT – 1) where i0 = 20 μA. The diode is operated at T = 300 K.

(a) Find the current through the diode when a voltage of 300 mV is applied across it in forward bias.


(b) At what voltage does the current double?


 23

Calculate the current through the circuit and the potential difference across the diode shown in figure. The drift current for the diode is 20 μA.


 25

Find the currents through the resistances in the circuits shown in figure.


 26

What are the readings of the ammeters A1 and A2 shown in figure? Neglect the resistances of the meters.