Questions from Electronics

Q: A metal bar of mass m slides frictionlessly on two parallel conducting

A metal bar of mass m slides frictionlessly on two parallel conducting rails a distance l apart (Fig. 7.17). A resistor R is connected across the rails, and a uniform magnetic field B,...

Q: Express the unit vectors rˆ, θˆ, φˆ in terms of

Express the unit vectors rˆ, θˆ, φˆ in terms of xˆ, yˆ, zˆ (that is, derive Eq. 1.64). Check your answers several ways (rˆ · rˆ =? 1, θˆ · φˆ =? 0, rˆ × θˆ =? φˆ,.. .). Also work out the in...

Q: A square loop of wire (side a) lies on a

A square loop of wire (side a) lies on a table, a distance s from a very long straight wire, which carries a current I , as shown in Fig. 7.18. (a) Find the flux of B through the loop....

Q: An infinite number of different surfaces can be fit to a given

An infinite number of different surfaces can be fit to a given boundary line, and yet, in defining the magnetic flux through a loop, / I never specified the particular surface to be used. Justify this app...

Q: Calculate the power (energy per unit time) transported down the

Calculate the power (energy per unit time) transported down the cables of Ex. 7.13 and Prob. 7.62, assuming the two conductors are held at potential difference V, and carry current I (down one and bac...

Q: Imagine an iron sphere of radius R that carries a charge Q

Imagine an iron sphere of radius R that carries a charge Q and a uniform magnetization M = M zˆ. The sphere is initially at rest. (a) Compute the angular momentum stored in the electromagne...

Q: Derive Eq. 8.39. [Hint: Treat the

Derive Eq. 8.39. [Hint: Treat the lower loop as a magnetic dipole.]

Q: Derive Eq. 8.43. [Hint: Use the

Derive Eq. 8.43. [Hint: Use the method of Section 7.2.4, building the two currents up from zero to their final values.]

Q: A very long solenoid of radius a, with n turns per

A very long solenoid of radius a, with n turns per unit length, carries a current Is . Coaxial with the solenoid, at radius b ((a, is a circular ring of wire, with resistance R. When the current in th...

Q: An infinitely long cylindrical tube, of radius a, moves at

An infinitely long cylindrical tube, of radius a, moves at constant speed v along its axis. It carries a net charge per unit length λ, uniformly distributed over its surface. Surrounding it, at radius...