Acoil of insulated wire is wound many times around an iron bar. the wire is connected to a battery and a contact switch. the contact switch is alternately flipped closed and left closed, so the wire carries a current through it, and then flipped open and left open, so that the current stops. describe what magnetic fields are created, if those magnetic fields in turn induce an emf, and whether the induced emf is in the direction of the original current or opposite
to it. justify your answer using lenz's law and the conditions which can cause a magnetic field to induce an emf. you may draw a diagram if it you to visualize the apparatus.

As per faraday's law the rate of change in magnetic flux linked with a coil will induce EMF in the coil. It is given by

now here as we are closing the switch and then open it alternatively so it will change the value of current in the coil.

This change in current will change the magnetic flux in the coil due to which it will induce EMF in it.

Now by Lenz the the direction of induce current in the coil will always opposite to the causes due to which it is induced.

As we know that when switch is connected to flow the current the direction of induced current is in opposite to the current so that it will oppose the increasing value of current while when we open the switch the induced current is in direction of the current so that it will increase the value of decreasing current in the loop.

so here is the information for current research:

-nrel's geothermal analysts, scientists, and engineers perform a full range of research from developing advanced methods of locating and accessing geothermal resources to exploring innovative technologies to extract and produce clean energy from the heat of the earth

and here is the information for the technology of geothermal energy:

-it's clean and sustainable

-resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma

-almost everywhere, the shallow ground or upper 10 feet of the earth's surface maintains a nearly constant temperature between 50° and 60°f (10° and 16°c)

-geothermal heat pumps can tap into this resource to heat and cool buildings

-a geothermal heat pump system consists of a heat pump, an air delivery system (ductwork), and a heat exchanger-a system of pipes buried in the shallow ground near the building

-in the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery system

-in the summer, the process is reversed, and the heat pump moves heat from the indoor air into the heat exchanger

-the heat removed from the indoor air during the summer can also be used to provide a free source of hot water

there are no contact forces mentioned on the list of choices that you've provided.