Zero Error and Correct Way to Measure Length

Q. The error that occurs when the length of an object is measured using a scale that has damaged zero mark is called:

1. Parallax error
2. Zero error
3. Numerical error
4. Angular error

Q. Rajesh measures the length of a box to be $30cm$ using a scale that has a broken left end. The actual length of the box is $29cm$. What is the zero error?

1. $1cm$
2. $30cm$
3. $29cm$
4. $59cm$

Q. While measuring the length of an object, if the zero mark of a scale does not coincide with one of the ends of the object, then such an error is called _____ error.

1. zero
2. instrumental
3. (a) and (b) above.
4. parallax

Q.

1 metre can be defined as distance travelled by light in $\frac{1}{299792458}$ seconds in vacuum.

1. True
2. False

Q.

Question 4

A piece of ribbon folded five times is placed along a 30 cm long measuring scale as shown in Fig.

The length of the ribbon is between:

(a) 1.15 - 1.25 m

(b) 1.25 - 1.35 m

(c) 1.5 - 1.6 m

(d) 1.6 - 1.70 m

Q.

Question 15

Four children measure the length of a table which was about 2 m. Each of them used different ways to measure it.

(i) Sam measured it with a half metre long thread.
(ii) Gurmeet measured it with a 15 cm scale from her geometry box.
(iii) Reena measured it using her hand span.
(iv) Salim measured it using a 5 m long measuring tape.

Which one of them would get the most accurate length? Give reason for your answer.

Q.

Question 9

You are provided three scales A, B and C as shown in Fig. to measure a length of 10 cm.

For the correct measurement of the length, you will use the scale,

(a) A only

(b) B only

(c) C only

(d) Any of three scales

Q.

Question 19

Three students measured the length of a corridor and reported their measurements. The values of their measurements were different. What could be the reason for the difference in their measurements?

Q.

Question 8

Which of the following figure shows the correct placement of a block along a scale for measuring its length?

(a)

(b)

(c)

(d)

Q.

Question 7

Four pieces of wooden sticks A, B, C and D are placed along the length of 30 cm long scale as shown in Fig. Which one of them is 3.4 cm in length?