Mechanical Devices
Bayani Gaba-gaba
Pick up a pair of nail clippers. Your thumb pushes down with a force you could apply all day, and at the other end two blades cut through a material that would blunt a kitchen knife. Nothing in the clippers generates any force at all. Every newton at the blades came from your thumb, and the clippers simply rearranged it, trading a long movement for a short one and a small force for a large one.
That trade is what mechanical devices do, and it is the whole of this lesson. You will learn the functions of mechanical devices that produce linear, rotary, reciprocating and oscillating movements, and how they change the magnitude and direction of force. You will meet levers of the first, second and third classes, linkages including bell cranks and push and pull arrangements, and rotary systems: cams and followers, simple gear trains, and pulleys and belts. You will calculate mechanical advantage, gear ratios and output speeds, and you will choose between three ways of doing the same job on a real product. This is core technical principles content, examined in Section A of Paper 1, where it supplied question 8 of the specimen paper.
Manufura
- The functions of mechanical devices to produce linear, rotary, reciprocating and oscillating movements.
- Changing magnitude and direction of force
- Levers:
- levers, first, second and third classes.
- Linkages:
- bell cranks
- push/pull.
- Rotary systems:
- cams and followers
- simple gear trains
- pulleys and belts.
Taswirar tunani
An zana wannan batu don ka ga yadda ra'ayoyi ke hadewa.
Bude taswirar tunani a cikin manhaja
Takardar Darasi
Cikakken Bayanin Darasi Yana Kan Manhajar Green Bridge
Sami manhajar Green Bridge CBT a wayarka ko kwamfutarka domin cikakken laburaren IGCSE: takardun jarrabawar baya, tsarin kimantawa, taswirar tunani, katunan karatu da darussan sauti.
Nazarin Darasi
Barka da kammala darasi akan Mechanical Devices. Yanzu da kuka bincika mahimman raayoyi da raayoyi, lokaci yayi da zaku gwada ilimin ku. Wannan sashe yana ba da ayyuka iri-iri Tambayoyin da aka tsara don ƙarfafa fahimtar ku da kuma taimaka muku auna fahimtar ku game da kayan.
Za ka gamu da haɗe-haɗen nau'ikan tambayoyi, ciki har da tambayoyin zaɓi da yawa, tambayoyin gajeren amsa, da tambayoyin rubutu. Kowace tambaya an ƙirƙira ta da kyau don auna fannoni daban-daban na iliminka da ƙwarewar tunani mai zurfi.
Yi wannan ɓangaren na kimantawa a matsayin wata dama don ƙarfafa fahimtarka kan batun kuma don gano duk wani yanki da kake buƙatar ƙarin karatu. Kada ka yanke ƙauna da duk wani ƙalubale da ka fuskanta; maimakon haka, ka kallesu a matsayin damar haɓaka da ingantawa.
- A windscreen wiper blade moves backwards and forwards along an arc. This motion is described as A. linear. B. oscillating. C. reciprocating. D. rotary. Answer: B
- In which class of lever is the load always between the fulcrum and the effort? A. First class B. Second class C. Third class D. All classes Answer: B
- A driver gear of 12 teeth meshes with a driven gear of 36 teeth. The driver turns at 600 revolutions per minute. What is the output speed? A. 100 revolutions per minute B. 200 revolutions per minute C. 1,800 revolutions per minute D. 3,600 revolutions per minute Answer: B
- Which cam gives the follower a period of dwell in every revolution? A. An eccentric cam B. A pear cam C. A snail cam D. No cam can Answer: B
- An idler gear is added between a driver and a driven gear. What is its effect? A. It doubles the output speed B. It halves the output torque C. It reverses the direction of the driven gear without changing the ratio D. It has no effect at all Answer: C
Yi aikin wadannan tambayoyi a cikin manhaja
Yi aikin wadannan tambayoyi a cikin manhaja
Littattafan da ake ba da shawarar karantawa
Yi Aikin Tambayoyin Gwaji
Kana son yin aikin tambayoyin gwaji kan Mechanical Devices? Sauke manhajar Green Bridge CBT don samun tambayoyin gwaji da cikakkun jarrabawa akan wannan batu.
Sauke Manhajar Daga Google Playstore
Duk abin da kake buƙata don yin fice a JAMB, WAEC & NECO.
