Error and Uncertainty

Q.

Plotter accuracy is measured in terms of repeatability and

1. Buffer size

2. Resolution

3. Vertical dimension

4. Intelligence

5. None of the above

Q. If the numerical value of the surface area of a cube is equal to the numerical value of the volume of the cube, then the numerical value of area of each face of the cube is:

1. $6$
2. $1$
3. $36$
4. $12$

Q.

A screw gauge with a pitch of 0.5 mm and a circular scale with 50 divisions is used to measure the thickness of a thin sheet of aluminium. Before starting the measurement, it is found that when the two jaws of the screw gauge are brought in contact, the ${45}^{th}$ division coincides with the main scale line and that the zero of the main scale is barely visible. What is the thickness of the sheet, if the main scale reading is 0.5mm and the ${25}^{th}$ division coincides with the main scale line?

1. 0.75 mm

2. 0.80 mm

3. 0.70 mm

4. 0.50 mm

Q.

Repeated observations in an experiment gave the values 1.29, 1.33, 1.34, 1.35, 1.32, 1.36, 1.30 and 1.33. Find the relative error.

1. 0.025

2. 0

3. 0.0175

4. 0.015

Q. The average marks scored by 5 students remain unchanged from 70 even when the marks scored by John and Anna are included. If John scored 10 marks more than Anna, find their scores.

Q.

In the determination of Young’s modulus $(Y=\frac{4MLg}{\pi l{d}^2})$ by using Searle’s method, a wire of length L=2m and diameter d=0.5mm is used. For a load M=2.5kg, an extension l=0.25mm in the length of the wire is observed. Quantities d and l are measured using a screw gauge and a micrometer, respectively. They have the same pitch of 0.5mm. The number of divisions on their circular scale is 100. The contributions to the maximum probable error of the Y measurement is:

1. Due to the errors in the measurement of d and l are the same

2. Due to the error in the measurement of d is twice that due to the error in the measurement of l

3. Due to the error in the measurement of l is twice that due to the error in the measurement of d

4. Due to the error in the measurement of d is four times that due to the error in the measurement of l

Q. A sphere and a cube have the same surface area. Find out the ratio of the volume of sphere to that to the cube.

1. $6:\pi$
2. $\sqrt{6}:\sqrt{\pi }$
3. $\sqrt{6}:\pi$
4. $6:\sqrt{\pi }$

Q.

Which team's measurements are more reliable?

1. Both are unreliable

2. Team A

3. Team B

4. Both are equally reliable

Q.

The period of oscillation of a simple pendulum in the experiment is recorded as 2.63 s, 2.56 s, 2.42, 2.71 s and 2.80 s respectively. Find the average absolute error.

1. 0.108 s

2. 0.11 s

3. none of these

4. 0.12s