Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Context: An electric transformer is a device that uses electromagnetic induction to change the voltage of electric current. Electromagnetic induction is the process of generating current with a magnetic field. It occurs when a magnetic field and electric conductor, such as a coil of wire, move relative to one another. A transformer may either increase or decrease voltage. You can see the basic components of an electric transformer in the Figure 1.1. Click image to the left or use the URL below. URL: The transformer in the diagram consists of two wire coils wrapped around an iron core. Each coil is part of a different circuit. When alternating current passes through coil P, it magnetizes the iron core. Because the current is alternating, the magnetic field of the iron core keeps reversing. This is where electromagnetic induction comes in. The changing magnetic field induces alternating current in coil S of the other circuit. Notice that coil P and coil S in the Figure 1.1 have the same number of turns of wire. In this case, the voltages of the primary and secondary currents are the same. Usually, the two coils of a transformer have different numbers of turns. In that case, the voltages of the two currents are different. When coil S has more turns than coil P, the voltage in the secondary current is greater than the voltage in the primary current (see Figure 1.2). This type of transformer is called a step-up transformer. Thats because it steps up, or increases, the voltage. When coil S has fewer turns of wire than coil P, the voltage in the secondary current is less than the voltage in the primary current (see Figure 1.3). This type of transformer is called a step-down transformer because it steps down, or decreases, the voltage. Q: Both step-up and step-down transformers are used in the electrical grid that carries electricity from a power plant to your home. Where in the grid do you think step-down transformers might be used? A: One place that step-down transformers are used is on the electric poles that supply current to homes. They reduce the voltage of the electric current before it enters home circuits. 
 Question: an electric transformer contains
an iron core.

Context: The story is not linked to the first part of the series. Instead, it focuses on a fictional explanation for the Ryanggang explosion in 2004, in which an unexplained mushroom cloud occurred in North Korea. After reconnaissance satellites detect a large, three-stage Topol intercontinental ballistic missile carrying a nuclear weapon in North Korea, which can strike anywhere in the continental United States, a fictional United States President Adair T. Manning (Peter Coyote) orders a team of U.S. Navy SEALs to destroy the missile and the launch site. The team is led by Lieutenant Robert James (Nicholas Gonzalez). The Pentagon aborts the mission after it receives new information, but by the time the abort order is sent, two SEALs have already parachuted into North Korean territory. James stops the third SEAL from deploying, accidentally knocking the man's helmet against the status indicator mounted near the door. The lieutenant steps onto the makeshift ramp to peer outside, returning to the doorway to inform the rest of men of the abort. The high-speed winds from outside rip the indicator loose and send it flying into the lieutenant's face. Stumbling backwards, James loses his balance and is sucked out of the plane. Callaghan disobeys orders to stand fast, strikes his commanding officer, and follows the first three, taking a radio with him. When North Korean forces led by Commander Hwang (Joseph Steven Yang) find the SEALs, two of the Navy SEALs are killed in a gun battle, and James and Callaghan are captured and tortured by Hwang and his men. After South Korean special forces rescue James and Callaghan, President Manning and the South Korean government send the SEALs and South Korean special forces to destroy the missile site. But after losing radio contact with the SEALs, the President and his top advisers believe that they have been captured again. Under pressure from his military advisor, General Norman Vance (Bruce McGill), the President decides to send B-2 stealth bombers to destroy the site, which would start a full-scale war against North Korea. The SEALs and the South Korean special forces are almost recaptured by Hwang, but he is shot by a defecting officer. James and the South Koreans destroy the missile silo with a bomb before the bombers reach the missile site, which averts the bombing and prevents a full-scale war. A tribunal convicts Callaghan of striking an officer (1 year) and disobeying an officer (10 years). Due to the "black op" nature of the mission, the transcript of the hearing is deemed classified and the charges are expunged from his record, leaving him free to return to his family. Meanwhile, James meets the president in a classified meeting, bringing his mentor Master Chief Scott Boytano (Keith David) as witness to James' receiving of an award. The film closes with Boytano telling James he wasn't red flagged because Boytano had never seen anyone who desired so badly as James did to be a SEAL. During the credits there is a news report on the Ryanggang explosion. 
 Question: Who destroys the missile silo?
james and the south koreans

Context: Flora Graeca was a publication of the plants of Greece in the late 18th century, resulting from a survey by John Sibthorp and Ferdinand Bauer. 
 Question: Who is the illustrator of Flora Graeca?

ferdinand bauer

