Cells in Series

Five identical cells each of internal resistance 1Ω and emf 5V are connected in series and in parallel with an external resistance 'R'. For what value of 'R', current in series and parallel combination will remain the same?

Two cells of emf E₁ and E₂ and internal resistances r₁ and r₂ are connected in parallel, with their terminals of the same polarity connected together. Obtain an expression for the equivalent emf of the combination.

First a set of n equal resistors of R each are connected in series to a battery of emf E and internal resistance R. A current I is observed to flow. Then the n resistors are connected in parallel to the same battery. It is observed that the current is increased 10 times. What is ‘n’?

Give reason/short answer.

In the given circuit diagram two resistors are connected to a 5V supply.

Calculate potential difference across the 8Ω resistor.

A 60 Ω resistor, a 1.0 H inductor and a 4 μF capacitor are connected in series to an ac supply generating an emf e = 300 sin (500t) V. Calculate:

1. impedance of the circuit.
2. peak value of the current flowing through the circuit.
3. phase difference between the current and the supply voltage.

Answer the following question.
Two bulbs are rated (P₁, V) and (P₂, V). If they are connected (i) in series and (ii) in parallel across a supply V, find the power dissipated in the two combinations in terms of P₁ and P₂.

Calculate force per unit length acting on the wire B due to the current flowing in the wire A.(See
Figure 2 below)

Two cells of emf’s approximately 5V and 10V are to be accurately compared using a potentiometer of length 400 cm.