Question

When two resistances of 100 ohm and 200 ohm are connected in series and then their combination is connected in parallel with 300 ohm resistance. Then the equivalent resistance of the combination will be ______ ohm.

Answer 1

Answer:

500 ohm

Explanation:

Change of a liquid into vapour state on gentle heating, such that liquid does not boil.Give one word answer for the following:

Answer 2

150 ohm.

In a series circuit, the output current of the first resistor flows into the input of the second resistor; therefore, the current is the same in each resistor and voltage is divided.

∴ V = V1 + V2

∴ IRe = IR1 + IR2

∴ Re = R1 +R2

∴ Re = 100 + 200

∴ Re = 300 ohm     ------ (i)

Now, this Re is connected in parallel with 300 ohm resistance.

In a parallel circuit, all of the resistor leads on one side of the resistors are connected together and all the leads on the other side are connected together and current is divided.

∴ I = I1 + I2

∴ $\frac{V}{Re}$ = $\frac{V}{R1}$ + $\frac{V}{R2}$

Here, R2 = Re

∴ $\frac{1}{Re}$ = $\frac{1}{R1}$ + $\frac{1}{Re}$

∴ $\frac{1}{Re}$ = $\frac{1}{300}$ + $\frac{1}{300}$

∴ Re = 150 Ohm