1.
When cooking food, microwaves ______________
Correct Answer
C. Operate at 2450 mhz.
Explanation
Microwaves operate at a frequency of 2450 MHz. This frequency is chosen because it allows the microwaves to efficiently penetrate and heat the food. The water molecules present in the food absorb the microwave energy and convert it into heat, cooking the food from the inside out. Additionally, microwaves use diodes to stop RF noise, but this is not the primary purpose of their operation. Convection is not involved in the heating process of microwaves.
2.
What is the primary mechanism by which microwave ovens heat food?
Correct Answer
D. Dielectric heating, where water molecules in food absorb microwave radiation.
Explanation
Microwave ovens heat food primarily through a process known as dielectric heating. This process involves microwave radiation, a form of non-ionizing electromagnetic radiation. Microwaves excite the water molecules within the food, causing them to rotate rapidly. This molecular motion generates heat through friction, effectively heating the food from the inside out. Unlike conventional ovens that heat food by conduction (heat transfer through direct contact) or convection (circulating hot air), microwaves utilize the dielectric properties of water molecules, making the heating process much faster and more efficient for certain types of food.
3.
The switches that are in the safety interlock are
Correct Answer
D. Called primary, secondary, and monitor.
Explanation
The switches in the safety interlock are referred to as primary, secondary, and monitor. This suggests that there are three types of switches present in the safety interlock system. The terms "primary," "secondary," and "monitor" are used to categorize and differentiate these switches based on their functions or roles within the interlock system.
4.
The best way to test a microwave high voltage diode ________.
Correct Answer
D. Is to use an analog meter with an internal 9-volt battery set on Rx10K.
Explanation
The best way to test a microwave high voltage diode is to use an analog meter with an internal 9-volt battery set on Rx10K. This is because an analog meter can accurately measure the resistance of the diode, which should be very high in one direction and low in the other. By setting the meter on Rx10K, it ensures that the diode's resistance can be accurately measured within the range of the meter. Using an analog meter with a 9-volt battery also provides a reliable power source for the measurement.
5.
A microwave oven with an open line fuse
Correct Answer
C. Will do nothing at all.
Explanation
If a microwave oven has an open line fuse, it means that the fuse is broken or disconnected, causing a break in the electrical circuit. As a result, the oven will not receive any power and will not function at all. It will not run hot or heat on low because it is not receiving any electrical current. Therefore, the correct answer is that the microwave oven with an open line fuse will do nothing at all.
6.
The four components contained in the high voltage area are
Correct Answer
B. Magnetron, high voltage transformer, diode, and capacitor.
Explanation
The correct answer is "magnetron, high voltage transformer, diode, and capacitor." These four components are typically found in the high voltage area of a device. The magnetron is responsible for generating microwaves, the high voltage transformer steps up the voltage, the diode converts AC to DC, and the capacitor stores electrical energy. Together, these components work together to produce and control the high voltage necessary for the device to function properly.
7.
What is the first thing to do when checking a turntable motor that isn't running?
Correct Answer
C. Check for the correct power at the motor.
Explanation
When checking a turntable motor that isn't running, the first thing to do is to check for the correct power at the motor. This is because if there is no power reaching the motor, it will not be able to function properly. By checking the power supply, one can determine if there is an issue with the electrical connection or if there is a problem with the power source. Once the power issue is resolved, further troubleshooting can be done if necessary.
8.
The interlock monitor switch _____________
Correct Answer
B. Must be closed when door is open.
Explanation
The interlock monitor switch must be closed when the door is open in order to ensure safety. This means that the switch should be in a closed position when the door is open, indicating that it is functioning properly and allowing the equipment to operate. If the switch is open when the door is open, it could indicate a fault or malfunction, which could potentially lead to unsafe conditions. Therefore, it is important for the switch to be closed when the door is open to maintain safety standards.
9.
A microwave that is heating ____________
Correct Answer
C. Will draw at least 9.5 amps.
Explanation
The phrase "will draw at least 9.5 amps" indicates that the microwave requires a minimum of 9.5 amps of electricity to function while heating. It implies that if the microwave is heating, it will consume at least 9.5 amps of power.
10.
When the internal line fuse is blown, it may be caused by ____________
Correct Answer
D. Both A & C are correct.
Explanation
When the internal line fuse is blown, it may be caused by a failed monitor switch and a shorted capacitor. A failed monitor switch can result in excessive current flow, leading to the blowing of the fuse. Similarly, a shorted capacitor can also cause a surge in current, causing the fuse to blow. Therefore, both options A and C are correct explanations for a blown internal line fuse.
11.
Identify this part found in a microwave.
Correct Answer
B. Diode
Explanation
A diode is a part found in a microwave that allows current to flow in only one direction. It acts as a switch, allowing electricity to flow from the transformer to the magnetron, which generates microwaves. The diode prevents the microwaves from flowing back into the transformer, protecting it from damage. Without a diode, the microwave would not be able to function properly.
12.
Identify this part found in a microwave.
Correct Answer
D. Capacitor
Explanation
A capacitor is a part found in a microwave that stores electrical energy. It is used to provide a high voltage supply to the magnetron, which is responsible for generating the microwave radiation. The capacitor charges up and then discharges this stored energy to the magnetron, allowing it to produce the necessary high-frequency waves for cooking. Without a capacitor, the microwave would not be able to function properly.
13.
Identify this part found in a microwave.
Correct Answer
A. Transformer
Explanation
A transformer is a part commonly found in a microwave. It is responsible for converting the high voltage electricity from the power source to a lower voltage that is suitable for the microwave's operation. The transformer helps to power various components of the microwave, such as the magnetron, which generates the microwaves for cooking. Without a transformer, the microwave would not be able to function properly.
14.
Identify this part found in a microwave.
Correct Answer
C. Magnetron
Explanation
A magnetron is a part found in a microwave that generates microwave radiation. It consists of a vacuum tube with a cathode and anode, and a magnetic field that causes electrons to move in a circular path. As the electrons interact with the resonant cavities in the magnetron, they generate microwaves. These microwaves are then directed into the cooking chamber of the microwave oven, where they heat and cook the food.
15.
A microwave cooks from the inside out.
Correct Answer
B. False
Explanation
Microwaves do not cook from the inside out. In fact, they work by emitting electromagnetic waves that excite the water molecules in food, causing them to vibrate and generate heat. This heat then cooks the food from the outside in, gradually penetrating towards the center. Therefore, the statement that microwaves cook from the inside out is false.