Solenoids: Consider a solenoid of length L, N windings, and radius b (L is much longer than b). A current I is flowing through the wire. If the length of the solenoid became twice as long (2L), and all other quantities remained the same, the magnetic field inside the solenoid would

Force on parallel wires: The figure shows three long, parallel, current-carrying wires. The current directions are indicated for currents I1 and I3. The arrow labeled F represents the net magnetic force acting on current I3. The three currents have equal magnitudes. What is the direction of the current I2?

Electric field and potential: If the electric potential in a region is given by V(x) = 6/x2, the x component of the electric field in that region is

Energy in capacitors: The capacitive network shown in the figure is assembled with initially uncharged capacitors. A potential difference, Vab = +100V, is applied across the network. The switch S in the network is kept open. Assume that all the capacitances shown are accurate to two significant figures. What is the total energy stored in the seven capacitors?

Field of a long wire: A very long thin wire produces a magnetic field of

Power: A series LRC ac circuit has a peak voltage of and a peak current of If the current lags the voltage by what is the average power of the circuit?

Dielectrics: A parallel-plate capacitor has a capacitance of 10 mF and is charged with a 20-V power supply. The power supply is then removed and a dielectric material of dielectric constant 4.0 is used to fill the space between the plates. What is the voltage now across the capacitor?

Electric field and potential : The graph in the figure shows the variation of the electric potential V(x) (in arbitrary units) as a function of the position x (also in arbitrary units). Which of the choices below correctly describes the orientation of the x-component of the electric field along the x-axis?

Dielectrics: A parallel-plate capacitor consists of two parallel, square plates that have dimensions 1.0 cm by 1.0 cm. If the plates are separated by

Electric field and potential: In a certain region, the electric potential due to a charge distribution is given by the equation V(x,y) = 2xy – x2 – y, where x and y are measured in meters and V is in volts. At which point is the electric field equal to zero?