Advertisements
Advertisements
प्रश्न
Explain a method to find the thickness of a hollow tea cup.
उत्तर
To find the thickness of a hollow teacup,
(i)Determine the pitch, of the least count and zero error of the screw gauge.
- Pitch of the screw = Distance moved by the pitch No. of rotations by Head scale
- Least count (LC) = 0.01 mm
- Zero error:
Positive zero error (ZE) = + (n × LC)mm = + (n × 0.01) mm
∴ Zero correction (ZC) = – (n × 0.01) mm
Negative zero error (ZE) = – (100 – n) × LC mm
∴ Zero correction (ZC) = (100 – n) × LC mm
(ii) Place the teacup between the two studs.
(iii) Rotate the head until the tea cup is held firmly but not tightly, with the help of ratchat.
(iv) Note the reading of the pitch scale crossed by the head scale (PSR) and the head scale
the division that coincides with the pitch scale axis (HSC).
(v) The thickness of the teacup is given by PSR + CHSR (Corrected HSR). Repeat the experiment for different positions of the teacup.
(vi) Tabulate the readings.
(vii) The average of the last column reading gives the thickness of the tea cup.
| S.No. | P.S.R
(mm) |
H.S.C
(division) |
CHSC = HSC ± ZC (Division) | CHSR = CHSC x LC (mm) | Total reading = PSR + CHSR (mm) |
| 1. | mean = mm | ||||
| 2. |
Thickness of the teacup = ……….. mm
APPEARS IN
संबंधित प्रश्न
Write an answer to the following question in your own words.
What precautions will you take to make accurate measurements in day-to-day affairs?
Explain, giving examples, the errors that occur while making measurements.
Give reasons.
It is not proper to measure quantities by using body parts as units.
Give reasons.
It is necessary to get the weights and measures standardized at regular intervals.
Explain the need for accurate measurement and the devices to be used for that.
The closeness of the measured value to the original value is _______.
Numerical Problem.
Find the thickness of a five rupee coin with the screw gauge, if the pitch scale reading is 1 mm and its head scale coincidence is 68.
Write a note on accuracy and precision.
Match the following.
| Column I | Column II |
| a) Temperature | Closeness to the actual value |
| b) Plane angle | Measure of hotness or coldness |
| c) Solid angle | Closeness to two or more measurements |
| d) Accuracy | Angle formed by the intersection of three or more planes |
| e) Precision | Angle formed by the intersection of two planes |
