电机与变压器英语练习题
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电机与变压器英语练习题
一、词汇填空
1. The ___________ is a device that converts electrical
energy into mechanical energy.
2. A ___________ is an electrical device that changes the
voltage of an alternating current.
3. The ___________ of a motor is the rotating part that
converts electrical energy into mechanical energy.
4. The ___________ of a transformer is the ratio of the
number of turns in the secondary coil to the number of turns
in the primary coil.
5. ___________ is the process of reducing the voltage of
electrical power for distribution.
二、选择填空
1. Which of the following is NOT a type of motor?
A. DC motor
B. AC motor
C. Transformer
D. Induction motor
2. The primary function of a transformer is to:
A. Increase voltage
B. Decrease voltage
C. Convert AC to DC D. Store electrical energy
3. In a threephase motor, the number of poles is
determined :
A. The frequency of the power supply
B. The voltage of the power supply
C. The speed of the motor
D. The type of motor
4. The slip of an induction motor is:
A. The difference between synchronous speed and actual
speed
B. The ratio of actual speed to synchronous speed
C. The ratio of synchronous speed to actual speed
D. The difference between rated speed and actual speed
5. Which of the following is a type of transformer
cooling method?
A. Air cooling
B. Water cooling
C. Oil cooling
D. All of the above
三、阅读理解
Passage:
1. What is the main function of a motor?
2. What are the two main types of motors? 4. Why are AC motors widely used in industrial and
residential settings?
四、翻译
1. 变压器是一种静止的电气设备，用于在两个或多个电路之间传输交流电能。
2. 电机的工作原理是基于电磁感应现象。
3. 三相异步电动机因其结构简单、运行可靠、维护方便等优点而得到广泛应用。
4. 变压器的效率通常高于95%，因此在电力系统中具有很高的经济价值。
5. 电动机的起动方式有直接起动、星角起动和自耦变压器起动等。
五、完形填空
1. A. power
B. voltage
C. current
D. speed
Motor starters are devices that protect __2__ during the
starting phase. They can limit the inrush current that occurs
when a motor is first turned on, which can prevent damage to
the motor windings and reduce the stress on the electrical
system.
2. A. motors
B. transformers
C. circuits D. starters
3. A. directonline (DOL)
B. stardelta
C. autotransformer
D. soft starter
In a stardelta starter, the motor starts in a __4__
configuration and then switches to a delta configuration once
it reaches a certain speed. This method reduces the starting
current and provides a smooth transition to fullspeed
operation.
4. A. star
B. delta
C. wye
D. series
For motors that require frequent starting and stopping,
__5__ starters are often used. These starters are designed to
handle the wear and tear associated with frequent operation.
5. A. DOL
B. stardelta
C. autotransformer
D. inversetime
六、段落匹配
Match the following descriptions with the correct terms.
Each term can be used only once. A. Induction Motor
B. Synchronous Motor
C. Transformer
D. Rectifier
E. Inverter
1. A motor whose speed is synchronized with the frequency
of the power supply.
2. A device that changes the AC voltage to a different AC
voltage level.
3. A motor that operates based on the principle of
electromagnetic induction.
4. A device that converts AC power to DC power.
5. A device that converts DC power to AC power.
七、句型转换
1. The efficiency of a transformer is usually higher than
95%. (改为一般疑问句)
3. The primary function of a transformer is to change the
voltage of an alternating current. (改为否定句)
4. Motors convert electrical energy into mechanical
energy. (改为反义疑问句)
5. Proper motor control can increase the lifespan of the
motor. (改为比较级)
八、写作 Write a short paragraph (about 5070 words) on the
importance of regular maintenance for electrical motors.
Include reasons why maintenance is crucial for the efficient
operation of motors.
答案
一、词汇填空
1. motor
2. transformer
3. rotor
4. turns ratio
5. voltage transformation
二、选择填空
1. C
2. A
3. A
4. B
5. D
三、阅读理解
1. The main function of a motor is to convert electrical
energy into mechanical energy.
2. The two main types of motors are DC motors and AC
motors.
4. AC motors are widely used in industrial and
residential settings due to their reliability and efficiency.
