A student performs an experiment to determine the density of a rectangular block. They measure the length as $12.12 ext{ cm}$, the width as $5.3 ext{ cm}$, and the height as $1.21 ext{ cm}$. The mass is measured as $50.2 ext{ g}$. The student calculates the volume and then the density. Which of the following correctly expresses the final calculated density with the appropriate number of significant figures?

Given, potential difference $V = \left( {8 \pm 0.5} \right)$ volt and current $I = \left( {2 \pm 0.2} \right)$. The value of resistance R is

A physical quantity P is given by $P = \frac{{{A^3}{B^{\frac{1}{{\;2}}}}}}{{{C^{ - 4}}{D^{\frac{3}{2}}}}}.$. The quantity which brings in the maximum percentage error in P is

The length and breadth of a rectangle are measured as 12.3 cm and 4.56 cm respectively. What is the area of the rectangle expressed with the correct number of significant figures?

The least count of a stop watch is 0.2 s. The time of 20 oscillations of a pendulum is measured to be 25 s. The percentage error in the measurement of time will be

A student measures the length of a rod as 25.00 cm using a vernier caliper with a least count of 0.01 cm. The student then uses a meter scale with a least count of 0.1 cm to measure the same rod. Which statement is true regarding the significant figures in these measurements?

How many significant figures are in the number 0.00420?

Round off 0.04567 to three significant figures.

The length of a cylinder is measured with a meter rod having least count 0.1 cm.Its diameter is measured with vernier callipers having least count 0.01 cm. Given that length is 5.0 cm. and radius is 2.0 cm. The percentage error in the calculated value of the volume will be

The velocity of transverse wave in a string is $v = \sqrt {\frac{T}{m},} \;$ where T is the tension in the string and m is mass per unit length. If T=3.0 kgf, mass of string is 2.5 g and length of string is 1.00m, then the percentage error in the measurement of velocity is

A thin copper wire of length $l$ metre increases in length by 2% when heated through ${10^{\rm{o}}}C.$. What is the percentage increase in area when a square copper sheet of length l metre is heated through ${10^{\rm{o}}}C.$