R = R1 + R2 + R3 = 4 + 3 + 1 = 8 Ω
Drop across R1 = 12 × 4/8 = 6 V
∴ VB = 12 − 6 = 6 V above ground
Drop across R2 = 12 × 3/8 = 4.5 V
∴ VC = VB − 4.5 = 6 − 4.5 = 1.5
Drop across R3 = 12 × 1/8 = 1.5 V
Different available load voltages are :
(i) VAB = VA − VB = 12 − 6 = 6 V
(ii) VAC = 12 − 1.5 = 10.5V
(iii) VAD = 12 V
(iv) VBC = 6 − 1.5 = 4.5 V
(v) VCD = 1.5 V