Answer the following question given this paragraph: 23.6 Back Emf It has been noted that motors and generators are very similar. Generators convert mechanical energy into electrical energy, whereas motors convert electrical energy into mechanical energy. Furthermore, motors and generators have the same construction. When the coil of a motor is turned, magnetic flux changes, and an emf (consistent with Faraday's law of induction) is induced. The motor thus acts as a generator whenever its coil rotates. This will happen whether the shaft is turned by an external input, like a belt drive, or by the action of the motor itself. That is, when a motor is doing work and its shaft is turning, an emf is generated. Lenz's law tells us the emf opposes any change, so that the input emf that powers the motor will be opposed by the motor's self-generated emf, called the back emf of the motor. (See Figure 23.25. Q: The motor thus acts as a generator whenever its coil does what? Choices: - stops - revolves - oscillates - rotates A:
rotates
Answer the following question given this paragraph: Vertebral Column Developmental anomalies, pathological changes, or obesity can enhance the normal vertebral column curves, resulting in the development of abnormal or excessive curvatures (Figure 7.21). Kyphosis, also referred to as humpback or hunchback, is an excessive posterior curvature of the thoracic region. This can develop when osteoporosis causes weakening and erosion of the anterior portions of the upper thoracic vertebrae, resulting in their gradual collapse (Figure 7.22). Lordosis, or swayback, is an excessive anterior curvature of the lumbar region and is most commonly associated with obesity or late pregnancy. The accumulation of body weight in the abdominal region results an anterior shift in the line of gravity that carries the weight of the body. This causes in an anterior tilt of the pelvis and a pronounced enhancement of the lumbar curve. Scoliosis is an abnormal, lateral curvature, accompanied by twisting of the vertebral column. Compensatory curves may also develop in other areas of the vertebral column to help maintain the head positioned over the feet. Scoliosis is the most common vertebral abnormality among girls. The cause is usually unknown, but it may result from weakness of the back muscles, defects such as differential growth rates in the right and left sides of the vertebral column, or differences in the length of the lower limbs. When present, scoliosis tends to get worse during adolescent growth spurts. Although most individuals do not require treatment, a back brace may be recommended for growing children. In extreme cases, surgery may be required. Excessive vertebral curves can be identified while an individual stands in the anatomical position. Observe the vertebral profile from the side and then from behind to check for kyphosis or lordosis. Then have the person bend forward. If scoliosis is present, an individual will have difficulty in bending directly forward, and the right and left sides of the back will not be level with each other in the bent position. Q: An excessive posterior curvature of the thoracic region is also known as what? Choices: - lordosis - babesiosis - osmosis - kyphosis A:
kyphosis
Q: Answer the following question given this paragraph: Ionic compounds are named for their positive metal ion first, followed by their negative nonmetal ion. Q: What kind of compounds are named for their positive metal ion first, followed by their negative nonmetal ion? Choices: - horizontal compounds - magnetic compounds - magnetic compounds - ionic compounds A:
A: ionic compounds
Question: Answer the following question given this paragraph: Q: What type of stress causes horizontal motions in strike-slip faults? Choices: - hot - cold - blunt - shear A:
Answer: shear
*Question*
Answer the following question given this paragraph: 32.4 Food Irradiation Ionizing radiation is widely used to sterilize medical supplies, such as bandages, and consumer products, such as tampons. Worldwide, it is also used to irradiate food, an application that promises to grow in the future. Food irradiation is the treatment of food with ionizing radiation. It is used to reduce pest infestation and to delay spoilage and prevent illness caused by microorganisms. Food irradiation is controversial. Proponents see it as superior to pasteurization, preservatives, and insecticides, supplanting dangerous chemicals with a more effective process. Opponents see its safety as unproven, perhaps leaving worse toxic residues as well as presenting an environmental hazard at treatment sites. In developing countries, food irradiation might increase crop production by 25.0% or more, and reduce food spoilage by a similar amount. It is used chiefly to treat spices and some fruits, and in some countries, red meat, poultry, and vegetables. Over 40 countries have approved food irradiation at some level. Food irradiation exposes food to large doses of. Q: Which radiations helps sterilize medical supplies? Choices: - gamma radiation - beta radiation - ions radiation - ionizing radiation A:
**Answer**
ionizing radiation
(Question)
Answer the following question given this paragraph: Ambrosia beetles live in the bark of trees. Like ants and termites, they grow fungi inside the bark of trees and use it to help digest their food. Q: Like ants and termites, they grow fungi inside the bark of trees and use it to help do what? Choices: - clean the nest - kill prey - weaken enemies - digest food A:
(Answer)
digest food