Title Advanced series 6th class Physics - Solutions.pdf ✅

Class 6 Physics Table of Content 1. Units and Measurements 1 – 24 2. Kinematics 25 - 61 3. Force and Newton’s Laws of Motion 62 - 85 4. Work, Energy, and Power 86 – 117 5. Heat 118 – 133 6. Light 134 – 144 7. Electricity 145 -153 8. Magnetism 154 - 164

Class 6 – Physics | A - 6 Units and Measurements 1 1.Units and Measurements Solutions LEVEL-I 1. Correct option: (A) To know and understand a physical situation completely, one is likely to measure the quantities such as distance, speed, time, mass, acceleration, force etc. which are called the physical quantities. Physical quantity is that in terms of which laws of physics can be expressed and which can be measured directly or indirectly. 2. Correct options: (A), (B), (C) Fundamental quantities are the quantities whose measurement is done with the independent units. The quantities in option: (D) Length, time and mass are measured by independent units such as kilogram, meter and second respectively. In all the other options velocity is there which is expressed in terms of derived units which is meters per second. So all the other sets cannot enter into the list of fundamental quantities in any system of units. 3. Correct option: (B) Mass is a physical quantity as it is used to measure a physical situation. Rest all are the emotional situations 4. Correct option: (A) Fundamental physical quantities are the quantities whose measurement does not depend on other physical quantities. For example, quantities Length, time and mass are measured independently and hence they are fundamental physical quantities. 5. Correct option: (B) Derived quantity is a quantity whose measurement is done with the help of other physical quantities and it can be obtained by writing the defining equation in terms of fundamental physical quantities. For example, velocity is a derived physical quantity which depends on fundamental quantities distance(length) and time. 6. Correct option: (B) Measurement is basically a comparison process. It involves the selection of a unit of measurement and comparing the quantity with standard unit. The standard chosen should be of the same nature as that of the quantity to be measured. For example, if we have to measure the length of a rod we have to take length as the standard quantity 7. Correct option: (A) In comparing the quantity with the standard unit, we have to find the number of times this unit is contained in the quantity. For example, suppose
Class 6 – Physics | A - 6 Units and Measurements 2 we have to measure the length of a wire AB and we select meter as the unit of measurement. We place the meter rod along the wire AB and find that it is contained 3 times in AB. Thus 3 is the numerical value of the length AB, when m is the unit of measurement. We write AB= 3 meter 8. Correct option: (B) The SI unit of temperature as per the International System of Units is Kelvin which is represented by the symbol K. 9. Correct option: (A) The standard chosen should be of the same nature as that of the quantity to be measured. For example, if we have to measure the length of a rod we have to take meter as the standard unit. 10. Correct option: (B) In general magnitude of a physical quantity (P)= numerical value × size of it’s unit. For example. If length of a rod = 3 m Then 3 = numerical value 1m = size of the unit 11. Correct option: (A) In general magnitude of a physical quantity (P)= numerical value(N) × size of it’s unit(U). Or P=NU For example. If length of a rod = 3 m Then 3 = numerical value 1m = size of the unit 12. Correct option: (C) As we know physical quantity (P)= numerical value(N) × size of it’s unit(U) Further we know that magnitude of a quantity remains the same, whatever may be the units of it’s measurement. Hence we may write P = N1U1 = N2U2 Where U1,U2 are the two unts of measurement of the same quantity and N1and N2are their respective numerical values. If U1 > U2 ,then N1 < N2 which means bigger is the unit , smaller is the numerical value and vice – versa. For example, Length of rod = 3 m = 300 cm Here, unit(m) is bigger and numerical value 3 is small Unit (cm) is small and numerical value 300 is bigger. Hence numerical value and size of unit are inversely proportional to each other.