Which of these letters is the symbol for current in equations a: c b: i c: r d: t

Ahuge (essentially infinite) horizontal nonconducting sheet 10.0 cm thick has charge uniformly spread over both faces. the upper face carries +95.0 nc/m2 while the lower face carries -25.0 nc/ m2. what is the magnitude of the electric field at a point within the sheet 2.00 cm below the upper face? (ε0 = 8.85 × 10-12 c2/n · m2)

Aloop of wire is in a magnetic field such that its axis is parallel with the field direction. which of the following would result in an induced emf in the loop? choose all that apply. a loop of wire is in a magnetic field such that its axis is parallel with the field direction. which of the following would result in an induced emf in the loop? choose all that apply. moving the loop outside of the magnetic field region. spin the loop such that its axis does not consistently line up with the magnetic field direction. change the magnitude of the magnetic field. change the diameter of the loop

On a mild saturday morning while people are working inside, the furnace keeps the temperature inside the building at 23degreesc. at noon the furnace is turned off, and the people go home. the temperature outside is a constant 16degreesc for the rest of the afternoon. if the time constant for the building is 3 hr, when will the temperature inside the building reach 18degreesc? if some windows are left open and the time constant drops to 2 hr, when will the temperature inside reach 18degreesc?