27. Resistors & DC Circuits

You need to design a 1.0 A fuse that 'blows' if the current exceeds 1.0 A. The fuse material in your stockroom melts at a current density of 500 A/cm². What diameter wire of this material will do the job?

Which type of electric current is typically produced by a standard chemical battery?

In a circuit consisting of a battery connected in series with a resistor and an ideal capacitor, what is the current through the battery after a very long time has passed?

A linear accelerator uses alternating electric fields to accelerate electrons to close to the speed of light. A small number of the electrons collide with a target, but a large majority pass through the target and impact a beam dump at the end of the accelerator. In one experiment the beam dump measured charge accumulating at a rate of −2.0 nC/s. How many electrons traveled down the accelerator during the 2.0 h run?

An aluminum wire consists of the three segments shown in FIGURE P27.64. The current in the top segment is 10 A. For each of these three segments, find the current density J. Place your results in a table for easy viewing.

A strip of silicon 1.8 cm wide and 1.0 mm thick is immersed in a magnetic field of strength 1.3 T perpendicular to the strip (Fig. 40–53). When a current of 0.28 mA is run through the strip, there is a resulting Hall effect voltage of 18 mV across the strip (Section 27–8). How many electrons per silicon atom are in the conduction band? The density of silicon is 2330 kg/m³.

A superconducting magnet carries a 100 A current through a 0.50-mm-diameter superconducting wire that is wound into a coil. How much charge flows through the wire in 15 minutes?

Which component is used to measure the current $I$ in a circuit?

In a simple circuit consisting of a battery with voltage $V$ and a resistor with resistance $R$ connected in series, what is the current through the battery?

In a series circuit, how does the total current change if additional resistors are added to the circuit, assuming the voltage source remains constant? $I$ is the current, $V$ is the voltage, and $R$ is the resistance, related by $I=\frac{V}{R}$.