Electrical engineering powers the technology we rely on every day, from smartphones to advanced medical devices. Resistors, a fundamental element in electrical circuits, are crucial for controlling current flow and ensuring circuits function properly, efficiently and safely.
In a series circuit, the total resistance is the sum of the individual resistances. In a parallel circuit, the total reciprocal resistance of the system is equal to the sum of the reciprocals of the individual resistances. Electrical resistance is measured in ohms, represented by the symbol Ω.
1.1 Riya, an electrical engineering student, is designing a prototype for a smartphone charger. To control the flow of current, Riya connects three resistors in series. The first resistor has a resistance of 150 Ω, the second has a resistance of 250 Ω and the third has a resistance of 75 Ω. What is the total resistance of the circuit, in ohms?
1.2 Riya decides to test a different configuration to see if it will improve the efficiency of the charging circuit. She replaces the series setup with a parallel connection using the same three resistors (150 Ω, 250 Ω and 75 Ω). What is the total resistance of the circuit in this new parallel configuration, in ohms? Express your answer as a decimal to the nearest hundredth.
1.3 Riya’s classmate, Emma, suggests a new design to optimize charging. The design involves two 100 Ω resistors connected in parallel, which are then connected in series with a 200 Ω resistor. This configuration will power a smartphone charging dock. What is the total resistance of this circuit, in ohms?