飛機潤滑油
2018-4-17 15:30:42
我覺得如果你有你之前做過嘅past paper 你可以睇返自己錯過啲乜 有啲咩題目會出啲伏位陰鳩你 盡量唔好令自己再錯(?)
移動巨砲
2018-4-17 15:33:37
實驗題要點溫同諗?
飛機潤滑油
2018-4-17 15:47:27
我諗你應該係講緊感生電流
首先你知唔知 1.一個線圈 (coil) 個current 喺順時針或者逆時針嗰陣邊一邊係north pole 邊一邊係south pole 呢個係由right hand grip rule 判斷嘅 2.North pole 係指出去, South(收) pole 係收返啲B-field
當你知道呢一樣野 你可以由Lenz's Law 開始了解起(應該係最容易上手)
佢個重點係 :oppose the change
只要一個coil 有magnetic flux change ( 通常都係諗做穿過佢嘅 多左定少左
例如 想像一個線圈喺個平面度 into paper 嘅B-field 多左 咁佢就會 oppose the change 想整返啲out of paper 嘅B-field 咁因為指出去嘅係North pole 咁所以North pole 會係指出嚟嗰個 即係個線圈會有current 而且係逆時針嘅
Faraday's Law 你明左呢個再講啦 我講到咁1999你都未必明 :( 歡迎補充
唔明再補圖
飛機潤滑油
2018-4-17 15:58:46
我覺得如果實驗題要攞滿分 一定要好熟書 又話者好了解實驗唔同嘅限制 或者設計會對結果有咩影響 e.g. 2016 比條毛巾都死左好多人 2014 唔知佢會有induce current 後會彈起 你成條都唔使做 你而家要温嘅話 我諗你都係睇下past paper 出面啲練習都可以 有時間可以貼下
2014 : magnetic
2015 : mechanics
2016 : heat
2017 : mechanics
好似magnetic 有啲耐未考過 你可以睇下啲實驗 鳩up e.g. DC motor ,睇下有咩因素會影響current 大細
至於大路答題flow 我會咁做:
1. describe the set up or how to connect the set up(e.g. connecting the wires, 黐膠紙)(呢個要睇下幅圖 佢有時啲野未駁好要你講埋點駁)
2. describe the way to implement the experiment(procedure) and what are you going to measure 記得量度係要度啲你儀器度到嘅野
3. write the expected result (如有)
4. explain the reason of having the expected result (think about if there are any formulae involved and write them out if there is any)
5. Precautions 如果佢叫你寫的話