Question

Three resistors 2 ohm , 4 ohm and 5 ohm are combined in parallel. What is the total resistance of the combination.


Physics-------Class 12th Unit 3 _Current Electricity_​

Answer 1

Answer:

Therefore,

Total resistance of parallel combination,

1R= 1R1+1R2+1R3 or 1R = 12+14+15 = 10+5+420 = 1920Ω

R = 2019Ω

ii) The combination is connected to a battery of 20 V.

Let the current through resistances 2Ω, 4Ω and 5Ω are I1, I2 and I3 respectively.

Now, using Ohm's law across each resistor we get,

I1 = VR1 = 202 = 10 AI2 = VR2 = 204 = 5 AI3 = VR3 = 205 = 4 A

Hence,

Total current is given by

I = I1+I2+I3 = 10+5+4 = 19A.