Cells in Series and Parallel — Prelims Questions

Three identical cells, each of EMF $2,\text{V}$ and internal resistance $0.5,Omega$, are connected in series to an external resistor of $R = 4.5,Omega$. What is the current flowing through the external resistor?

Two cells, one with $E_1 = 10,\text{V}$ and $r_1 = 1,Omega$, and another with $E_2 = 4,\text{V}$ and $r_2 = 2,Omega$, are connected in series. If the positive terminal of the first cell is connected to the positive terminal of the second cell, what is the equivalent EMF of the combination?

Four identical cells, each of EMF $1.5,\text{V}$ and internal resistance $0.2,Omega$, are connected in parallel. This combination is connected to an external resistor of $R = 0.4,Omega$. What is the current flowing through the external resistor?

A mixed grouping of cells consists of 3 rows in parallel, with each row containing 2 identical cells in series. Each cell has an EMF of $1.0,\text{V}$ and an internal resistance of $0.1,Omega$. If this combination is connected to an external resistor $R = 0.1,Omega$, what is the total current drawn from the combination?

Which of the following statements is TRUE regarding the connection of cells?

A battery pack is formed by connecting 4 rows in parallel, with each row containing 5 identical cells in series. Each cell has an EMF of $1.5,\text{V}$ and an internal resistance of $0.1,Omega$. What is the equivalent EMF and equivalent internal resistance of this battery pack?