Home › HSC (New South Wales) › Physics › Electrical Circuits › In a flashlight, the batteries are normally conn…
In a flashlight, the batteries are normally connected one after the other (in series) rather than in parallel. Why?
ASeries connection gives a lower combined voltage and power output
BSeries connection is only possible with rechargeable batteries
CSeries connection gives a higher combined voltage and power output
DSeries and parallel give identical voltage, so it makes no difference
Answer & Solution
Correct answer: C. Series connection gives a higher combined voltage and power output
1. Two 9-V batteries connected one after the other are stated elsewhere to combine to give 18 V, their voltages simply adding.
2. Connecting batteries in parallel instead would keep the voltage at a single battery's rating, not add the voltages together.
3. A higher combined voltage supports a higher power output, since power depends on voltage.
4. So batteries are connected in series in a flashlight for a higher combined voltage and power output.
_Source: OpenStax Physics (CC BY 4.0), Ch 19 "Electrical Circuits", section 19.4 Electric Power_
Related questions
Three 10 ohm resistors are connected in parallel across a 9.0 V battery. What power is disIn that same six-resistor circuit, the middle branch dissipates 2.4 W, the left branch disSix 30 ohm resistors are wired into three branches connected in parallel across a 12 V batA single 9-V alkaline battery can deliver a charge of 565 mA h. Two of these batteries areYou want 10 W of heat output from a resistor heater powered by two 9-V batteries connectedHousehold outlets in many countries supply 120 V AC. What does it mean that this 120 V figAn older incandescent light bulb is rated at 60 W and operates at 120 V. What current flowA 25-W light bulb and a 60-W light bulb both operate at the same voltage. Which bulb has t