The number of significant figures in the quantity $0.00005041 \ J$ is

In an experiment on a simple pendulum to determine the acceleration due to gravity,a student measures the length of the thread as $63.2 \,cm$ and the diameter of the pendulum bob as $2.256 \,cm$. The student should take the length of the pendulum to be ........... $cm$.

The area of a square is $5.29\ cm^2$. The area of $7$ such squares taking into account the significant figures is ........... $cm^2$.

For an experimental expression $y=\frac{32.3 \times 1125}{27.4}$,where all the digits are significant. Then to report the value of $y$,we should write $:-$

An object of mass $m = 3.513 \ kg$ moves along the $x$-axis with a velocity of $5.00 \ ms^{-1}$. The magnitude of its momentum can be recorded as $...... \ kg \ ms^{-1}$.

Length,breadth,and thickness of a strip having a uniform cross-section are measured to be $10.5 \ cm$,$0.05 \ mm$,and $6.0 \ \mu m$,respectively. Which of the following option$(s)$ give$(s)$ the volume of the strip in $cm^3$ with correct significant figures?