This is an MCQ-based quiz on the topic of Electricity: Electric Circuits and cost of electricity.
This set of MCQs helps you brush up on the important physics topics and prepare you to dive into skill practice and expand your knowledge.
How much energy would be transferred by a computer of power 50 W running for 8 hours in joules?
In order to reduce their electricity bill, a home owner changed their electricity supplier who gave them a cheaper rate for any electricity they used between midnight and 6 a.m. This electricity cost only 8p per unit compared to 12p per unit at other times. How much would they have saved if from a total of 589 units 289 had been used at the cheaper price in pounds?
How many units of electricity would be used by a 2 kW electric fire switched on for 30 minutes?
A particular kettle has a power rating of 5 kW. It takes 3 minutes to boil enough water for a cup of tea. How much would it cost if electricity costs 10p per unit in pounds?
If an appliance consumes (transfers) electrical energy at a rate of 8 kWh and electricity costs 8 pence per unit. What is the cost of running it for 3 hours in pounds?
A coffee cup immersion heater utilizes a heating coil with a resistance of 8.5 Ω. Determine the current through the coil in ampere when operated at 110 V.
A power saw at the local hardware store boasts of having a 15-Amp motor. Determine its resistance in ohm when plugged into a 110-Volt outlet.
The heating element of an electric toaster is typically made of nichrome wire (an alloy of nickel and chromium). As current passes through the wires, the wires heat up, thus toasting the toast. Estimate the overall resistance in Ω of a heating element which is 220 cm long and consists of nichrome wire with a diameter of 0.56 mm. The resistivity of nichrome is 110x10-8 Ω•m.
The large window air conditioner in Anita Breeze's room draws 11 amps of current. The unit runs for 8.0 hours during the course of a day. Determine the quantity of charge to the power of 10 that passes through Anita's window AC during these 8.0 hours.
Over the course of an 8 hour day, 3.8x104 C of charge pass through a typical computer (presuming it is in use the entire time). Determine the current for such a computer in A.