An idealized ammeter is connected to a battery as shown in Fig. E25.28
. Find (b) the current through the 4.00-Ω resistor.

The circuit shown in Fig. E25.33

contains two batteries, each with an emf and an internal resistance, and two resistors. Find (a) the current in the circuit (magnitude and direction)

The current in a wire varies with time according to the relationship I = 55 A - (0.65 A/s^2)t^2. (b) What constant current would transport the same charge in the same time interval?

The current in a wire varies with time according to the relationship I = 55 A - (0.65 A/s^2)t^2 . (a) How many coulombs of charge pass a cross section of the wire in the time interval between t = 0 and t = 8.0 s? (b) What constant current would transport the same charge in the same time interval?

An idealized ammeter is connected to a battery as shown in Fig. E25.28

. Find (c) the terminal voltage of the battery.

An idealized ammeter is connected to a battery as shown in Fig. E25.28

. Find (a) the reading of the ammeter.

A proton moves along the x-axis with vₓ = 1.0 x 10⁷ m/s.. As it passes the origin, what are the strength and direction of the magnetic field at the (x, y, z) positions (a) (1 cm, 0 cm, 0 cm), (b)(0 cm, 1 cm, 0 cm), and (c) (0 cm, -2 cm, 0 cm)?

What is the magnetic field at the position of the dot in FIGURE EX29.6? Give your answer as a vector.

As a proton passes the origin, its velocity is $3.0\times {10}^5\mathrm{m}/\mathrm{s}$in the positive x direction. What is the magnitude of the magnetic field at the point ($12.0\mathrm{cm}$, $5.0\mathrm{cm}$, $0.0\mathrm{cm}$)?