Exam 25: Current,resistance,and Electromotive Force

The current supplied by a battery as a function of time is What is the total number of electrons transported from the positive electrode to the negative electrode from the time the battery is first used until it is essentially dead? (e = 1.60 × 10^-19 C)

In an electroplating process,copper (ionic charge +2e,atomic weight 63.6 g/mol)is deposited using a current of 10.0 A.What mass of copper is deposited in 10.0 minutes? Avogadro's number is and e = 1.60 × 10^-19 C.

A Nichrome wire is used as a heating element in a toaster.From the moment the toaster is first turned on to the moment the wire reaches it maximum temperature,the current in the wire drops by 20.0% from its initial value.What is the temperature change in the wire? The temperature coefficient of resistivity for Nichrome is 0.000400 (°C)^-1.

The emf and the internal resistance of a battery are shown in the figure.If a current of 7.8 A is established through the battery from b to a,what is the terminal voltage V_ab of the battery?

A light bulb is connected to a 110-V source.What is the resistance of this bulb if it is a 100-W bulb?

The voltage and power ratings of a particular light bulb,which are its normal operating values,are 110 V and 60 W.Assume the resistance of the filament of the bulb is constant and is independent of operating conditions.If the light bulb is operated at a reduced voltage and the power drawn by the bulb is 36 W,what is the operating voltage of the bulb?

What must be the diameter of a cylindrical 120-m long metal wire if its resistance is to be ? The resistivity of this metal is 1.68 × 10^-8 Ω • m.

A wire of resistivity ρ must be replaced in a circuit by a wire of the same material but 4 times as long.If,however,the resistance of the new wire is to be the same as the resistance of the original wire,the diameter of the new wire must be

A tube of mercury with resistivity 9.84 × 10^-7 Ω • m has an electric field inside the column of mercury of magnitude 23 N/C that is directed along the length of the tube.How much current is flowing through this tube if its diameter is 1.0 mm?

The voltage and power ratings of a particular light bulb,which are its normal operating values,are 110 V and 60 W.Assume the resistance of the filament of the bulb is constant and is independent of operating conditions.If the light bulb is operated with a current that is 50% of the current rating of the bulb,what is the actual power drawn by the bulb?

When electric current is flowing in a metal,the electrons are moving

How much current will be flowing through a 40.0 m length of cylindrical metal wire with radius 0.0 mm if it is connected to a source supplying 16.0 V? The resistivity of this metal is

The emf and the internal resistance of a battery are as shown in the figure.When the terminal voltage V_ab is equal to 17.4 V,what is the current through the battery,including its direction?

The figure shows a 2.0-cm diameter roller that turns at 90 rpm.A 4.0-cm wide plastic film is being wrapped onto the roller,and this plastic carries an excess electric charge having a uniform surface charge density of 5.0 nC/cm².What is the current of the moving film?

A certain fuse "blows" if the current in it exceeds 1.0 A,at which instant the fuse melts with a current density of What is the diameter of the wire in the fuse?