Class 11 Physics Unit & measurment: NCERT Solutions for Question 10

This page focuses on the detailed Unit & measurment question answers for Class 11 Physics Unit & measurment, addressing the question: 'State the number of significant figures in the following: (a) 0.007 m2 (b) 2.64 x 1024 kg (c) 0.2370 g cm-3 (d) 6.320 J (e) 6.032 N m-2 (f) 0.0006032 m2'. The solution provides a thorough breakdown of the question, highlighting key concepts and approaches to arrive at the correct answer. This easy-to-understand explanation will help students develop better problem-solving skills, reinforcing their understanding of the chapter and aiding in exam preparation.
Question 10

State the number of significant figures in the following:(a) 0.007 m2(b) 2.64 x 1024 kg(c) 0.2370 g cm-3(d) 6.320 J(e) 6.032 N m-2(f) 0.0006032 m2

The given quantity is 0.007 m2.

If the number is less than one, then all zeros on the right of the decimal point (but left to the first non-zero) are insignificant. This means that here, two zeros after the decimal are not significant. Hence, only 7 is a significant figure in this quantity.

The given quantity is 2.64 x 1024 kg.

Here, the power of 10 is irrelevant for the determination of significant figures. Hence, all digits i.e., 2, 6 and 4 are significant figures.

The given quantity is 0.2370 g cm-3.

For a number with decimals, the trailing zeroes are significant. Hence, besides digits 2, 3 and 7, 0 that appears after the decimal point is also a significant figure.

The given quantity is 6.320 J.

For a number with decimals, the trailing zeroes are significant. Hence, all four digits appearing in the given quantity are significant figures.

The given quantity is 6.032 Nm-2.

All zeroes between two non-zero digits are always significant.

The given quantity is 0.0006032 m2.

If the number is less than one, then the zeroes on the right of the decimal point (but left to the first non-zero) are insignificant. Hence, all three zeroes appearing before 6 are not significant figures. All zeros between two non-zero digits are always significant. Hence, the remaining four digits are significant figures.