The numbers \(2.745\) and \(2.735\) on rounding off to \(3\) significant figures will give respectively, 

1.	\(2.75\)  and \(2.74\)	2.	\(2.74\)  and \(2.73\)
3.	\(2.75\) and \(2.73\)	4.	\(2.74\) and \(2.74\)

The mean length of an object is \(5~\text{cm}.\) Which of the following measurements is the most accurate?

The mass and volume of a body are \(4.237~\text{g }\) and \(2.5~\text{cm}^3,\) respectively. The density of the material of the body in correct significant figures will be:
1. \(1.6048~\text{g cm}^{-3}\)
2. \(1.69~\text{g cm}^{-3}\)
3. \(1.7~\text{g cm}^{-3}\)
4. \(1.695~\text{g cm}^{-3}\)

Time intervals measured by a clock give the following readings: 
\(1.25~\text{s},~1.24~\text{s}, ~1.27~\text{s},~1.21~\text{s},~1.28~\text{s}.\) 
What is the percentage relative error of the observations? 
1. \(2\)%
2. \(4\)%
3. \(16\)%
4. \(1.6\)%

The dimensions of ${\left({\mu }_0{\epsilon }_0\right)}^{-1/2}$ are:

1.  $[$ $L^{-1}T$ $]$

2.  $[$ $L{T}^{-1}$ $]$

3.  $[$ $L^{1/2}{T}^{1/2}$ $]$

4. $[$ $L^{1/2}{T}^{-1/2}$ $]$

Which of the following measurements is the most precise?

1. 5.00 mm

2. 5.00 cm

3. 5.00 m

4. 5.00 km

The dimensions of \((\mu_0\varepsilon_0)^{\frac{-1}{2}}\) are:
1. \(\left[L^{-1}T\right]\)
2. \(\left[LT^{-1}\right]\)
3. \(\left[L^{{-1/2}}T^{{1/2}}\right]\)
4. \(\left[L^{{-1/2}}T^{{-1/2}}\right]\)

The length, breadth, and thickness of a rectangular sheet of metal are \(4.234\) m, \(1.005\) m, and \(2.01\) cm respectively. The volume of the sheet to correct significant figures is:
1. \(0.00856\) m³${}^{}$
2. \(0.0856\) m³${}^{}$
3. \(0.00855\) m³${}^{}$
4. \(0.0855\) m³${}^{}$

We measure the period of oscillation of a simple pendulum. In successive measurements, the readings turn out to be \(2.63~\text s, 2.56~\text s, 2.42~\text s, 2.71~\text s,\) and \(2.80~\text s.\) The average absolute error and percentage error, respectively, are:
1. \(0.22~\text s\) and \(4\%\)
2. \(0.11~\text s\) and \(4\%\)
3. \(4~\text s\) and \(0.11\%\)
4. \(5~\text s\) and \(0.22\%\)