IB DP Physics Questions

5.3 Electric Cells

Question 1

Which of the following best describes the primary function of a chemical cell?

A. Convert mechanical energy to electrical energy

B. Convert electrical energy to mechanical energy

C. Convert chemical energy to electrical energy

D. Convert electrical energy to chemical energy

Question 2

The EMF of a cell is 1.5V, but when connected to a circuit, its terminal voltage drops to 1.2V. What is the most likely cause of this drop?

A. External resistance is too high

B. The cell is fully charged

C. Internal resistance of the cell

D. The cell is not connected properly

Question 3

Two identical cells, each of EMF 1.5V and negligible internal resistance, are connected in series. What is the total potential difference across the combination?

A. 0.75V

B. 1.5V

C. 3.0V

D. 6.0V

Question 4

Which of the following best describes the electrode reaction in a chemical cell?

A. Physical change at the electrode

B. Mechanical movement at the electrode

C. Chemical reaction at the electrode

D. Electrical discharge at the electrode

Question 5

Why is the terminal voltage of a cell usually less than its EMF when supplying current to an external circuit?

A. Due to the chemical reactions in the cell

B. Because of the magnetic field around the cell

C. Due to the internal resistance of the cell

D. Because of the external resistance of the circuit

Question 6

a) Describe the fundamental chemistry behind a chemical cell and explain how energy conversion takes place within it. [3]

b) A chemical cell has an electrode potential of 1.5 V. If a current of 2 A flows through it for 10 seconds, calculate the amount of charge that has passed through the cell. [2]

Question 7

a) Differentiate between electromotive force (EMF) and terminal voltage of a cell. [3]

b) A battery with an EMF of 9 V and an internal resistance of 1 ohm is connected to an external resistor of 8 ohms. Calculate the terminal voltage of the battery. [2]

Question 8

a) Explain the significance of combining cells in series and parallel. [3]

b) Two identical cells, each with an EMF of 1.5 V and negligible internal resistance, are connected in parallel. What is the resultant EMF of the combination? [2]

Question 9

a) Describe the role of electrode reactions in the functioning of a chemical cell. [3]

b) If a chemical cell has an internal resistance of 0.5 ohms and is connected to an external load of 4.5 ohms, calculate the total resistance of the circuit. [2]

c) Given that the EMF of the cell is 3 V, determine the current flowing through the circuit. [2]

Question 10

a) Explain the difference between resistivity and conductivity and their significance in the context of electrical circuits. [3]

b) A material has a resistivity of 1.7 x 10^-8 ohm.m. Calculate its conductivity. [2]

c) How does temperature generally affect the resistivity of metals? [2]