Page 28 - Introduction to Physics

4. Table shows the readings of the length of a rod as recorded by two students, X and Y

Reading of student X/cm Reading of student Y/cm

2.42 2.43

2.38 2.41

2.40 2.38

2.36 2.34

a) What was the instrument used by both students?

b) Why four readings were taken for each measurement?
c) What is the average value of the readings made by

i) student X ?
ii) student Y ?
d) Which set of reading is more accurate? Why?

e) Apart from the instrument in (a), what instruments can be used although they are
less accurate?

Answers :

a) Vernier caliper
b) To increase the accuracy
c) (i) student X (ii) student Y ?

. 2 42  . 2 38  . 2 40  . 2 36  . 2 39 cm . 2 43  . 2 41  . 2 38  . 2 34  . 2 39 cm

4 4

d) Both are same accurate. Their average readings are the same.
e) Meter ruler 28