1. What is the use of Spirit Levels?
a) Angular measurements only
b) Static leveling only
c) Static leveling of equipment and angular measurement
d) Finding roundness of rotating parts
Explanation: Spirit level is the device which is used to measure small inclination or angle of tilt and also used for the static leveling of machineries. It has a sealed glass tube and a scale is engraved on it.
2. How sensitivity of spirit level is expressed?
a) Angle in seconds/1 division of tube
b) Angle in minutes/2 divisions of tube
c) Angle in minutes/1 division of tube
d) Angle in seconds/2 divisions of tube
Explanation: Sensitivity of a spirit level is the angle of tilt in seconds to the 1 division of tube i.e. bubble will move by 1 division of the tube. One division = about 2.5 mm
3. Where the bubble rests on the scale when spirit level is placed horizontally?
a) Left most
b) Centre
c) Right most
d) Bottom
Explanation: A scale is engraved on the glass of spirit level tube and bubble rests at centre position. When the spirit level is tilted through a small angle then this bubble will always try to remain at the highest position.
4. What is the range of base length of type-1 spirit level?
a) 20-90 mm
b) 100-200 mm
c) 200-300 mm
d) 200-500 mm
Explanation: 3 types of spirit level are specified by BS-1958 in which type-1 spirit level has base length in the range of 100-200 mm and type-2 has base length between 200-500 mm.
5. If angle of tilt is equal to 10 seconds of arc and length of one division is equal to 2.5 mm in a spirit level then what is radius of tube?
a) 51.5 m
b) 51.5 mm
c) 25.5 m
d) 25.5 mm
Explanation: If radius of tube is R then, arc l is equal to Rα where α is taken in seconds. 1 radian is approximately equal to the 206,265 seconds of arc. 10 sec. = 0.0000485 radian. Tilt = 2.5 mm/R. By this, R = 51.5 m approximately.
6. Which of the following is used as a replacement of spirit vial in electrical level?
a) Steel rule
b) Protractor
c) Square block
d) Pendulum
Explanation: In an electrical level, a pendulum is present in place of spirit vial. Displacement of a pendulum is amplified by electrical means or electrically. A separate meter is used to show the readings.
7. What is the length of electronic precision levels?
a) 100 mm
b) 200 mm
c) 300 mm
d) 400 mm
Explanation: Electronic precision level is of about 200 mm length with 0.01 mm/m numerical division. Measuring range of electronic precision level is ±1.99 mm/m. It shows the stability of the indication after 3 seconds.
8. What is the maximum measuring error in electronic precision level?
a) ≤ ± 5% of indicated measuring value
b) ≥ ± 10% of indicated measuring value
c) ≤ ± 20% of indicated measuring value
d) ≥ ± 15% of indicated measuring value
Explanation: Electronic precision level has an LCD digital display with maximum measuring error of less than or equal to ±5% of indicated measuring value. Electronic precision level are used to obtain high accuracy. Measuring range is large.
9. Which of the following given statement is true/false about the sensitivity of spirit level?
Statement 1: Sensitivity of the spirit level increases as the radius of tube increases.
Statement 2: Spirit levels are insensitive to the temperature variation.
a) F, F
b) F, T
c) T, F
d) T, T
Explanation: Sensitiveness of the spirit level is decided by its tube radius. Variation in temperature will cause change in tension of ether vapours in the tube of a spirit level. So, spirit levels are very sensitive to temperature change
10. Which of the following is true for spirit level?
a) The tube is completely filled with the liquid
b) The Liquid almost fills the tube
c) One-fourth part of the tube is filled with liquid
d) One-tenth part of the tube is filled with liquid
Explanation: The glass tube of spirit level is almost filled by liquid, there is a bubble at the highest position of the tube. The movement of the bubble along the tube radius depends upon the angle of tilt.