With same emf of 10 V, a combination of two batteries with different internal resistances of 20 ohm and 5 ohm, is attached to parallel combination of 30 ohm and R ohm. Find value of R.

As per the given question, the following can be represented:

• The emf of two batteries = 10 V
• Internal resistances of Two batteries = 20 Ω and 5 Ω
• Parallel combination = 30 Ω and R Ω.
• Voltage Difference across the battery of internal resistance 20 Ω = zero

Parallel Combination of Resistors

Now, in order to determine the value of R:

E₁ = E – ir

E₂ = E – ir

= 10 – i20 = 0

= 10 – 0.5 × 5

i = 0.5 A

= 7.5 V

Thus,

E_net = E₁ + E₂ = 7.5 V

⇒ i = i₁ + i₂ 

⇒ 0.5 = (7.5/x) + (7.5/30)

⇒ R = 30 Ω

---

Related Questions

1. X and Y, which are two resistors, with resistances of 2 Ω and 3 Ω respectively are first connected in parallel and then in series. In both cases, the voltage that is supplied is 5 V. (i) Illustrate a circuit diagram to show the combination of resistors. (ii) Calculate the amount of voltage across 3 Ω resistor in the series combination of resistors.
2. In An Arrangement Of Resistances, Find Effective Resistance Between Points A and B.
3. What Is Effective Resistance?
4. Two Identical Resistors With Resistances 15 Ohm Are Connected In Series And Parallel To A Battery Of 6 V. Calculate Ratio Of Power Consumed.
5. A Circuit Consists Of A Battery Of 3 Cells (2 V Each), A Combination Of Three Resistors, 10 Ohm, 20 Ohm And 30 Ohm, Attached Parallelly, With Plug Key And Ammeter (In Series).

---

Also Check: