Precision and Accuracy

Q. How are systematic errors minimised?

1. Errors can't be minimised.
2. Changing equipment/method
3. Taking an average
4. Testing a larger group of people.

Q. Which of the following is most accurate?

1. $20\times {10}^1\text{m}$
2. $0.2\times {10}^3\text{m}$
3. $200.0\text{m}$
4. $2\times {10}^2\text{m}$

Q. A student measured the length of a rod and wrote it as $3.50\text{cm}$. Which instrument did he use to measure it ?

1. A vermier calliper where the $10$ divisions in vernier scale matches with $9$ division in main scale and main scale has $10$ divisions in $1\text{cm}$
2. A screw gausge having 100 divisions in the circular scale and pitch as $1\text{mm}$
3. A meter scale
4. A screw gauge have 50 divisions in the circular scale and pitch as $1\text{mm}$

Q.

Calculate the temperature which has same numeral value on Celsius and Fahrenheit scale.

Q.

Measurement is the comparison of an unknown quantity with an unknown quantity called

1. unit

2. physical quantity

3. symbol

4. magnitude

Q.

A vernier scale has 10 divisions. It slides over the main scale, whose$1\mathrm{M}.\mathrm{S}.\mathrm{D}.\mathrm{is}1.0\mathrm{mm}$. If the number of divisions to the left side of the zero of the vernier scale on the main scale is $49\mathrm{and}\mathrm{the}8\mathrm{th}$vernier scale division coincides with the main scale, calculate the length in centimetres.

Q.

If the smallest measurement that can be measured by using a scale is $0.1\mathrm{mm},$then the length of $1\mathrm{m}$in the scale is divided into_______ equal parts.

1. 1000

2. 5000

3. 10000

4. 50000

Q.

The quantity that can be measured is called ____________ quantity

Q.

A Vernier caliper has 25 divisions on the Vernier scale. An object is held between the external jaws of this instrument. If the zeroth division of the Vernier scale is to the left of the ${32}^{\mathrm{nd}}$division of the main scale and the ${20}^{\mathrm{th}}$division of the Vernier scale coincides with the main scale division, determine the measurement of the object.$(\mathrm{Take}1\mathrm{M}.\mathrm{S}.\mathrm{D}.=0.5\mathrm{mm})$

Q. A steel scale measures the length of a copper wire as $80cm$ when both are at ${20}^{\circ }C$ (the calibration temperature for scale). What would be the scale read for the length of the wire when both are at ${40}^{\circ }C?$ (Given ${\alpha }_{steel}=11\times {10}^{-6}{/}^{\circ }C$and ${\alpha }_{copper}=17\times {10}^{-6}{/}^{\circ }C$

1. $1cm$
2. $25.2cm$
3. $80.0096cm$
4. $80.0272cm$

Q.

In a Vernier caliper, $15$ Vernier scale divisions correspond to $14$ main scale division, and one main scale division is equal to $1.5\mathrm{mm}.$ An object held between the external jaws of the given Vernier calipers. If the zeroth division of the Vernier scale is to the left of the ${20}^{\mathrm{th}}$ division of the main scale, find the measurement of the object; if the 14th division of the Vernier scale coincides with the main division.

Q.

Name a convenient unit $t$to be used to measure the length of a room in your house.

Q.

While measuring the length of the knitting needle, the reading of the scale at one end is $3.0cm$ and at the other end is $33.1cm$. What is the actual length of the needle?

Q. Which of the following is correct about the correct measurement of length?

1. Measuring your classmate's height using long wooden scale
2. All of the above
3. Measuring your classmate's height using a small scale of $30cm$ long
4. Measuring your classmate's height using a long steel rod

Q.

The zeroth division of a vernier scale lies between the${40}^{\mathrm{th}}\mathrm{and}{41}^{\mathrm{st}}$main scale division. Then, the $\mathrm{M}.\mathrm{S}.R=4\mathrm{cm}\mathrm{if}\mathrm{M}.\mathrm{S}.\mathrm{D}.=1\mathrm{mm}$.

1. True
2. False

Q. In a Vernier calipers, one main scale division is
m cm and n divisions of Vernier scale coincides with (n – 1) divisions of the main scale. Minimum reading that can be taken from this Vernier caliper is

1. $\frac{mn}{n-1}$
2. $\frac{m}{n}$
3. $\frac{(n-1)m}{n}$
4. $\left(\frac{m}{n-1}\right)$

Q. Zero error of Vernier calliper is

1. -0.1 mm
2. 0.1 mm
3. -0.3 mm
4. 0.3 mm