1. Errors in measurement include instrumental errors, observational errors, random errors, and systematic errors. 2. Instrumental errors arise from defects in measurement instruments and include zero errors, backlash errors, and level errors. 3. Observational errors are due to personal factors of the observer and conditions of observation. 4. Random errors occur unpredictably while systematic errors are due to defects in instruments or measurement methods and produce consistent bias. 5. The accurate value of a measured quantity accounts for the measurement error and can be calculated using formulas provided.

1. c`v_©weÁvb
1g cÎ
welq †KvW: 174

2. Physical World and
Measurement
‡fŠZRMr I
cwigvc
অধ্যায় - 1
6ô K¬vm

3. wkLb dj
GB cvV †k‡l wkÿv_©xiv -
• cwigv‡ci ÎæwU wK Zv ej‡Z cvi‡e
• cwigv‡ci wewfbœ ÎæwU e¨vL¨v Ki‡Z cvi‡e
• cwigvc¨ ivwki ï×Zi gvb m¤ú‡K© ej‡Z
cvi‡e|

4. cwigv‡ci ÎæwU
Errors in measurement
K. hvwš¿K ÎæwU (Instrumental Error)
L. ch©‡eÿYg~jK ÎæwU (Observational Error)
M. G‡jv‡g‡jv ÎæwU (Random Error)
N. cybive„wËK ÎæwU (Systematic Error)

5. Instrumental Error
1. ïb¨ ÎæwU (Zerro error)
2. wcQU ÎæwU (Backlash error)
3. †j‡ej ÎæwU (Level error)
(K)
95
0
5
(L)
95
0
5
(M)
95
0
90
hvwš¿K ÎæwU

6. ch©‡eÿYg~jK ÎæwU
Observational Error
1. e¨vw³MZ ÎæwU
2. cÖvšÍ `vM ÎæwU
3. j¤^b ÎæwU
A B
1 2 3 4 5
wPÎ- 1 (fyj c×wZ)(K) (L)
A B
1 2 3 4
wPÎ- 2 (mwVK c×wZ)
(K) (L)

7. G‡jv‡g‡jv ÎæwU
Random Error

8. cybive„wËK ÎæwU
Systematic Error
1. hvwš¿K Kvib
2. cixÿY †KŠkj ev c×wZ Kvi‡Y
3. e¨vw³MZ KviY
4. jwNô Myb ÎæwU

9. cwigvc¨ ivwki ï×Zi gvb
Accurate value of measurement quantity
ÎæwUi kZKiv nvi = %100
~

x
yx
GLv‡b,
x = cÖK…Z ivwki gvb
y = cwigvc¨ ivwki gvb

10. cwigvc¨ ivwki ï×Zi gvb
Accurate value of measurement quantity
xxL 
x
x
eError L

, valueal
Change
Error
Re

%100, 


x
x
eError L
kZKiv wnmv‡e,
x
Small division in desire scale

11. cwigvc¨ ivwki ï×Zi gvb
Accurate value of measurement quantity
xyA 
y
x
B 
y
y
x
x
ee BA




n
xP  xP nee If then

12. cwigvc¨ ivwki ï×Zi gvb
Accurate value of measurement quantity
3
3
4
r
M

  rm eee 3

13. g~j¨vqb
1. cwigv‡ci ÎæwU wK?
2. cwigv‡ci wewfbœ ÎæwUi bvg ej?
3. cwigvc¨ ivwki ï×Zi gvb wK?

14. mw¤§wjZ KvR
1. c„w_exi Nb‡Z¡i kZKiv ÎæwU †ei Ki|
[c„w_exi fi=5.975×1024kg Ges
e¨vmva©=6400km]

15. evwoi KvR
 ¯øvBW K¨vwjcvm© I ¯Œ-M‡Ri hvwš¿K ÎæwU
m¤ú‡K© hv Rvb wjL|