Exam 17: Dc Circuits

A 4.0-Ω resistor is connected with a 12-Ω resistor and both of these are connected across an ideal dc power supply with voltage V as shown in the figure.If the total current through this circuit is I = 2.0 A,what is the current through the 4.0-Ω resistor?

Two resistors in series are equivalent to 9.0 Ω,and in parallel they are equivalent to 2.0 Ω.What are the resistances of these two resistors?

When unequal resistors are connected in series across an ideal battery,

A 120-Ω laboratory resistor is rated at 0.25 W.What is the safe current through the resistor?

Calculate the current through a 10.0-m long 22-gauge nichrome wire with a radius of 0.321 mm if it is connected across a 12.0-V battery.The resistivity of the nichrome is 1.00 × 10^-6 Ω ∙ m.

Four resistors are connected across an ideal dc battery with voltage V,as shown in the figure.If the total current in this circuit is I = 1 A,what is the value of the voltage V?

What is the resistance of 1.0 m of a solid cylindrical metal cable having a diameter of 0.40 inches and a resistivity of 1.68 × 10^-8 Ω ∙ m?

A flashlight draws 0.133 A from a 3.0-V battery pack.In 2.0 minutes (a)how much charge flows from the battery,(b)how much energy does the battery supply,and (c)how many electrons have passed any point in the circuit every second?

A battery has an emf ε = 12 V and an internal resistance r = 2.0 Ω,as shown in the figure.When a current of 6.0 A is drawn from the battery,the terminal voltage of the battery V_ab is closest to

As more resistors are added in series to a constant voltage source,the power supplied by the source

What is the equivalent resistance in the circuit shown in the figure?

For the circuit shown in the figure,the current in the 8.0-Ω resistor is 0.50A.What is the current through the 2.0-Ω resistor? All the numbers shown are accurate to two significant figures.

A 2.0-Ω resistor is in series with a parallel combination of 4.0-Ω,6.0-Ω,and 12-Ω resistors.What is the equivalent resistance of this system?

The figure shows a graph of the power dissipated in a resistor as a function of the resistance.What quantity does the slope of this graph represent?

You are given a copper bar of dimensions 3 cm × 5 cm × 8 cm and asked to attach leads to it in order to make a resistor.If you want to achieve the smallest possible resistance,you should attach the leads to the opposite faces that measure

A 200-W light bulb is connected across a 110-V dc power supply.What is the current through this bulb?

For the circuit shown in the figure,calculate the emf's ε₁ and ε₃,assuming that the batteries are ideal.Note that two currents are shown.

Three resistors of resistances 4.0 Ω,6.0 Ω,and 10 Ω are connected in parallel.If this combination is now connected in series with an ideal 12-V battery and a 2.0-Ω resistor,what is the current through the 10-Ω resistor?

If emf of the ideal battery is V = 100 V,what is the potential difference across R₅ for the circuit shown in the figure?

A resistance heater is rated at 1200 W when operating at 110 V dc.What current will it draw?