Question: how do you pop popcorn boil water for tea or...
How do you pop popcorn, boil water for tea, or heat up
leftovers? If you answered, "In the microwave oven," you're cooking
with the "wave" of the future. What are microwaves, and how do they
Microwaves are one of many different forms of energy that occur in nature. Other forms include visible light, radio waves, and X-rays. Microwaves are very short waves, hence the prefix micro-, which means "small." When microwaves hit water molecules, for example, the water molecules begin to bounce around, hitting against one another. Something hitting against something else causes friction. Friction produces heat, which can be used to cook food.
A microwave oven has a few essential parts. First is the cooking chamber, constructed in such a way that the microwaves cannot escape into the surroundings. Next is a magnetron, a magnet that is used to generate microwaves. The microwaves pass through a wave guide that leads them to the top of the oven, where they strike a rotating disk, which looks something like a propeller. This scatters the waves throughout the oven.
How do microwaves cook? Microwaves are absorbed by the water, fats, and sugars in food and are converted into heat, which cooks the food. Because most plastics, glass, and ceramics do not absorb microwaves, the microwaves heat food without heating the container or the inside of the oven. If a container is hot when you take it out of the microwave oven, it is because the hot food has conducted heat to the container.
There are some drawbacks to cooking with microwaves. For one thing, the waves penetrate unevenly into thick pieces of food, so some parts of the food may be undercooked. Also, traditional ovens cook food from the outside to the inside, allowing foods to brown or form a crust on the outside. Because microwaves penetrate the food, they do not brown the outside or form a crust. However, many foods prepared for microwave cooking are packages with a special sleeve, which will become hot from the cooking food and allow the crust to become crispy.
Most professional chefs do not cook with microwave ovens, but they do admit the microwave is good for some things, especially for warming leftovers.
Question 1. What is the main idea of the second paragraph?
a. Microwaves are a form of energy
b. The prefix micro means small
c. One thing hitting against another produces friction
d. Microwaves do not form a crust on food
Question 2: How do microwaves produce heat
a. They cause molecules to bounce around, producing friction.
b. They strike a rotating disk in the cooking chamber
c. They heat food but not the container that holds the food
d. They are a form of energy that occurs in nature.