Electric Circuits Answers

Explain how the back emf of a motor causes the development of mechanical power.

A tungsten filament bulb rated at 500w, 100v is to be connected in series to a capacitor across 220v, 50hz supply. Calculate the capacitor such that the voltage and power consumed by the bulb are according to the rating of the bulb

a tesla car needs to charge its 350-volt model and must send about 715 amps through its cabling to the battery. how many electrons pass through the cable for the current involved.

two identical incandescent light bulbs, each with resistance R=2Ω, are connected to as source with E= 8V and negligible internal resistance. find the current through each bulb is the bulb are connected in series.

two identical incandescent light bulbs, each with resistance R=2Ω, are connected to as source with E= 8V and negligible internal resistance. find the current through each bulb is the bulb are connected in series.

You have a wire with a cross-sectional area of 0.10 mm2. If there are 4.0 × 1028 atoms per cubic meter in this wire, and if each atom contributes 2 free electrons, what is the drift velocity of the electrons when the current in the wire is 6.0 A?

B. Using a hydrogen atom as an example, compare the gravitational 

and the electrostatic forces between a proton and and electron

In the manufacture of copper wire a 5 m length of thick circular rod, which has a resistance of

 0.02 ohm is drawn out without change in volume until its new diameter is one-tenth of what it

 was. Calculate the length of the drawn conductor and its resistance. [Ans: 200 Q]

How many electrons per second pass a point in a circuit when a current of 1.60A is established in the circuit? (Charge on an electron = 1.6x 10^-19 C)

Section 3: (10 marks) Word Problem

Target response size: text portion approximately 1 - 2 paragraphs (or equivalent) of explanation, plus maths portion showing your work

Four electrical devices are connected to powerpoints wired into the same electrical supply circuit. This is a standard Australian residential building circuit rated at 10 A. The devices have power ratings of 200 W, 740 W, 330 W and 1150 W. Can all four devices be operated at the same time on this circuit?