Force, Work, Power and Energy
Work, Power and Energy
Refraction of Light Through Plane Surface
Refraction of Light Through a Lense
Electricity and Magnetism
Electrical Power and Energy and Household Circuits
- Concept of Electrical Power and Household Circuits Numericals
- Household Circuits - Colour Coding of Wires
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- Earthing (Grounding)
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- Alternating Current (A.C.) Generator
- Current Electricity
- Resistors in Series
- single fixed, single movable, block and tackle; MA, VR and η in each case
Give reason for the following:
In case of a block and tackle arrangement, the mechanical advantage increases with the increase in the number of pulleys.
(a) Fig represents an incomplete diagram of a simple string pulley system. Copy this diagram on a new page and complete it and mark where the effort must be applied to lift the load.
(b) What is the velocity ratio of this system?
(c) If the pulley system is 80% efficient and the load is 720 N, then
(i) What effort must be applied to lift the load?
(ii) What work must be done must be done in lifting the load through a distance of 2 m using this machine?
The diagram below shows a pulley arrangement.
(i) In the diagram, mark the direction of the forces due to tension, acting on the pulley P.
(ii) What is the purpose of the pulley Q?
(iii) If the tension is T newton, deduce the relation between T and E.
(iv) Calculate the velocity ratio of the arrangement.
(v) Assuming that the efficiency of the system is 100%, what is the mechanical advantage?
(vi) Calculate the value of E