Find the current through the resistance R in figure if (a) R = 12 Ω (b) R = 48 Ω


fig1.png


Net potential difference across arm PQ is negative.


• The diode is reverse biased.


• No current flows through arm PQ


Net resistance = (R + 12) Ω


(a) R=12Ω
Net resistance =12+12 =24Ω
Current= (4V+6V)/24Ω = 0.42A


(b) R=48Ω
Net resistance=48+12 = 60Ω
Current= (4V+6V)/60Ω = 0.16A


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