 Vector operations

Vector operations Addition of vectors:  If two scalars are added resulting scalar will be unique which will be equal to sum of the given two scalars. For examples if two scalars 2 and 8 are added their sum will be always  equal to 2+8 =10. But, the addition of vectors is complicated. If we add two […]

Units and Dimensions Multiple choice questions

Multiple choice questions – Units&Dimensions. (Also Useful for entrance preparation) 1 . 1KWH is  unit of Ans : 1.Time 2. Power 3. Energy 4. Stress 2. Unit of  Intensity of magnetic induction field  is Ans : 1.N/Am  2. Tesla   3.Wb/    4. All above 3. Which of the following has no units? Ans : 1. Thermal capacity    […]

Types of Units

Types of Units Generally we can use any convenient unit to measure a physical quantity depending on how much magnitude we are measuring or in which system of units we want to measure it. What kind of unit we should use? The unit i) must be accepted internationally. ii) Should be reproducible. iii) Should be invariable. […]

Units in different systems

Units in different systems Generally we can use any convenient unit to measure a physical quantity depending on how much magnitude we are measuring or in which system of units we want to measure it. What kind of unit we should use? The unit i) must be accepted internationally. ii) Should be reproducible. iii) Should be […]

Special Units

Special Units 1. Length: Micron( )= m = cm Angstrom (A) = m = cm Fermi = m = cm Astronomical Unit (A.U) = (1.5) m  = (1.5) cm;                                                                                                       What is 1 A.U. ?                                                                                                                                                                                                                                Ans: 1 A.U(Astronomical Unit) is the distance between Earth and Sun. 1A.U=(1.496) km. X ray unit (X.U) = m (wave […]

Units & Dimensions Q&A

Units & Dimensions Q&A 1. What is a physical quantity?Ans : Any quantity which is measurable is called physical quantity. 2. Explain the term Fundamental Physical quantity.Ans: The physical quantity which is independent or which can not be derived from any other physical quantity is called fundamental physical quantity. EX: Mass, Length and Time. 3.Explain the […]

Physics in Every Day Life

1.Does hot water put out a fire faster than cold water? Ans:Yes.When fire is caught if you sprinkle cold water,the water first absorbs heat from the flame and gets heated to boiling point.Then it absorbs heat further and becomes vapor.Once it is vaporized it occupies that region around the flame.Because of this,availability of oxygen around […]

Numerical Problems-Bodies in vertical motion

Problems-Bodies in vertical motion 1.A stone is projected vertically upwards with a velocity 29.4m/sec. i)Calculate the maximum height to which it rises  ii) calculate the time taken to reach maximum height iii) Find the ratio of velocities after 1sec, 2 sec, 3sec of its journey. Soln: From the data given in the problem,Initial velocity of stone […]

Problems Linear motion

Problems Linear motion In this post and  in few of my posts to come, I would like to solve problems on linear motion,freely falling bodies,vertically projected up bodies and projectiles . 1.An object accelerates from rest to a velocity 20m/sec in 4seconds.If  the   object  has uniform acceleration, find its acceleration and displacement in this time. Soln: […]

Kinematics Introduction and more…

Kinematics Introduction and more… 1.The terms Rest & Motion are relative terms. There is no object in the universe  which is at absolute rest.Ex: A text book in a book rack may be  relatively at rest, with respect to the immediate surroundings. But, the earth is revolving  around sun, therefore every particle on earth will […]