Question

Calculate the effective resistance of the following combination of resistances and the voltage drop across each resistance when a P.D. of 60 V is applied between points A and B.

Answer 1

Resistance between A and C (Fig. 1.17). 

= 6 || 3 = 2 Ω 

Resistance of branch ACD = 18 + 2 = 20 Ω 

Now, there are two parallel paths between points A and D of resistances 20 Ω and 5 Ω. 

Hence, resistance between A and D = 20 || 5 = 4 Ω 

∴ Resistance between A and B = 4 + 8 = 12 Ω 

Total circuit current = 60/12 = 5 A 

Current through 5 Ω resistance = 5 x 20/25 = 4A

Current in branch ACD = 5 x 5/25  = 1A 

∴ P.D. across 3 Ω and 6 Ω resistors = 1 × 2 = 2V 

P.D. across 18 Ω resistors = 1 × 18 = 18V 

P.D. across 5 Ω resistors = 4 × 5 = 20V 

P.D. across 8 Ω resistors = 5 × 8 = 40V

Comments

So what is the full answer