Conceptual Questions | Physics 9th | Chapter 1 | Physical Quantities & Measurements | KPK Textbook

1. Choose the best possible option. How many millimeters are there in 10cm? (a) 100mm (b) 200mm (c) 50mm (d) 10mm Which of the following quantity can be measured using a micrometer? (a) current (b) force (c) length (d) mass The instrument best measures the internal diameter of a pipe is (a) screw gauge (b) vernier caliper (c) meter rule (d) measuring tape Which prefix represents a largest value? (a) mega (b) giga (c) peta (d) exa Which of the following is the smallest prefix? (a) atto (b) pico (c) nano (d) femto Which of the following numbers shows one significant digit? (a) 1.1 (b) 6.0 (c) 7.1 (d) 6×〖10〗^2 Which of the following numbers shows 4 significant digits? (a) 900.8 (b) 4 (c) 5174.00 (d) 0.0002 A light year is distance traveled by light in one year. It travels about 9.460×〖10〗^15 m. How many significant figures are in this number? (a) 6 (b) 2 (c) 3 (d) 4 0.2mm in units of meters is (a) 0.0002m (b) 2×〖10〗^(-4) m (c) none (d) both A and B KITAB UL MANAZIR is the name of book written by (a) Yaqub Kindi (b) ibnal Haitham (c) Al Beruni (d) none 2. Give a brief response to the following questions How technology is shaped by physics? Physics and biology are considered different branches of science, how physics links with biology? Why are measurements important? Why area is a derived quantity? Name any four derived units and write them as their base units? Why in physics we need to write in scientific notation? What is least count? How least count for vernier calliper and screw gauge are defined? How can we find the volume of a small pebble with the help of measuring cylinder? Write the number in prefix to power of ten. a. Mechanical nano-oscillators can detect a mass change as small as 〖10〗^(-21) kg. b. The nearest neutron star is about 3.00×〖10〗^18 m away from Earth. c. Earth to sun distance is 149.6 million km. An angstrom is a unit of length (commonly used in atomic physics), defined as 〖10〗^(-10) m which is of the order of the diameter of an atom. a. How many nanometers are in 1.0 angstrom? b. How many femtometers or fermis (the common unit of length in nuclear physics) are in 1.0 angstrom? c. How many angstroms are in 1.0m? The speed of light is c=299,792,458 〖ms〗^(-1). a. Write this value in scientific notation. b. Express the speed of light to 1. Five significant figures, 2. Three significant figures. Express the following in terms of powers of 10. a. 7 nanometer b. 96 megawatt c. 2 gigabite d. 43 picofarad e. 2 millimeter Write the following numbers in standard form: a. Mass of Bacterial call: 0.000,000,000,005kg b. Diameter of Sun: 1,390,000,000m