1. Multiple choice questions: (Each question has only one correct answer, each question 1 point, ***50 small questions)
1. When the oxygen content of water gas and semi-water gas in the gas generating station reaches ▁ ▁, the boiler must be stopped.
a . 0.5% b . 0.7% c . 1% d . 1.2%
Answer: c
Analysis: P4
2. Connect the uncharged metal part of electrical equipment with the protective zero line of the power grid, which is called _ _ _ _.
A. protective grounding B. working zero connection C. working grounding D. protective zero connection
Answer: d
Analysis: P 16
3. It is safer to use the _ _ _ _ _ shape for the planer body of the hand-fed woodworking planer.
A. hexagonal prism B. quadrangular prism C. polygonal prism D. cylinder
Answer: d
Analysis: P52
4._ _ _ _ _ V safe voltage should be used in metal containers, tunnels, wells and places with large area grounding conductors, narrow workplaces and inconvenient movement; _ _ _ _ _ V safe voltage should be used in special places such as water work.
a . 12 6 b . 36 24 c . 42 24d . 36 12
A: A.
Analysis: P 19 P384
5._ _ _ _ is the main lightning protection measure for various power transformation and distribution devices.
A. use lightning rod B. use valve arrester C. use lightning protection belt D. use lightning protection network
Answer: b
Analysis: P22
. . . . . .
Second, multiple-choice questions: (2 points for each question, 2-4 correct answers for each question, 1 0.5 point for each correct answer, 2 points for all correct answers, and no score for one wrong answer)
7 1. The distance between the belt guard and the belt should not be less than 50mm, and the design should be reasonable so as not to affect the operation of the machine. Need to set up protection is _ _ _ _. ( )
A. the pulley spacing is greater than 3m;
B bandwidth is above 15 cm;
C belt rotation speed is higher than 9m/min.
D. The pulley diameter is greater than 0.5m
E. the transmission mechanism is below 2m from the ground.
Answer: ABCE
Analysis: P9
72. The following power supply can be used as a safe power supply is _ _ _ _.
A. autotransformer
B. voltage divider
C. storage battery
D. Safety isolating transformer
E. power transformer
Answer: C D
73. The leakage protection device is mainly used for _ _ _ _.
A. Prevent personal electric shock accidents
B. Preventing power interruption
C. Reduce line loss
D. Preventing fire accidents caused by leakage
E. monitoring ground fault.
Answer: Ade
Analysis: P 19
74. The control measures of dust hazards in industrial production process are _ _ _ _. ( )
A. shielding operation
B. Wet operation
C. adopt a closed, ventilated and dust-removing system.
D. Use a vacuum cleaner
E. Wear a dust mask
Answer: BCE
Analysis: P53
75. The development process of building fire generally includes _ _ _ _.
A. initial period
B. Development period
C. peak period
D. extinction period
E. reignition period
Answer: ABCD
Analysis: P66
. . . . . .
Part two (multiple choice questions): multiple choice questions
I. Mine Safety Major
5 1. The voltage of the distribution network at all levels in the coal mine and the rated voltage level of all kinds of electrical equipment shall meet the high voltage of no more than _ _ _ _ V; Low pressure does not exceed _ _ _ _ v.
a . 1000380
6000，660
C. 10 000， 1 140
d . 100006000
Answer: c