Physics 6 HTS

 Exercises 1. When is work done by a force ? Answer-Work is done by a force  when the point of application of a force moves through a distance. 2. Name two things which store chemical energy. Answer -Food and fuels store chemical energy. 3. Name three forms of energy. Answer- Three forms of energy - Solar energy, Chemical energy and Electrical energy. 4.Define a Machine. Answer-A machine is a device through which of force applied at a point over comes resistance some other point. 5.Name four categories of machine Answer-Four categories of machine - 1. Lever 2. Wedge 3. Screw 4. Wheel and axle 6.What is a Lever ? What is it's fulcrum? Answer - A Lever is a rigid body capable of rotating about a point on itself .The fulcrum of a lever is the point about which can rotate. 7.What is load and effort in the context of a Machine? Answer - The effort is the force applied to a machine and the load is the resistance overcome by a machine. 8.What is the basis on which levers are divided ...

    Class 6 Magnetism Question – Answer Short-Answer Questions 1.       State two possible origins of the term 'magnetism'. Answer-   .1.As early as 800 BC, the ancient Greeks probably knew that magnetite, an iron ore mined in the province of Magnesia, attracted iron.   2.Magnet was derived either from Magnesia, or from Magnes, the name of the shepherd who supposedly discovered magnetism when the iron tip of his stick and the nails of his shoes stuck to some rocks containing magnetite. 2. Name three elements that are magnetic materials. Answer- Three elements that are magnetic materials - Iron, cobalt and nickel 3. How is magnetism of help in navigation? Answer- Directional property is the principle for magnetic compass formation which always points to earth's North , helping in navigation 4. What is the basic difference between the magnetic properties of iron and steel? Answer-   Unlike Iron , steel is able to retain its magnetism perma...