Qua cac de thi trac nghiem tot nghiep THPT mon vat ly tu nam 2007 den nay, chung ta tam duc ket cach lam bai sao cho nhanh va hop ly.
Mot tiet lam bai kiem tra cuoi hoc ky cua hoc sinh Truong THPT Hoang Hoa Tham – TPHCM.
Chu y phuong phap giai tong quat
Truoc het, phai doc tong quat that nhanh toan bo de va to san nhung cau ly thuyet biet chac chan dung. Nhung cau tim phat bieu sai thi to len chu sai de sau do coi lai cho chac. Sau do, nen lam ly thuyet truoc vi ly thuyet chiem khoang tren 40% noi dung de. Nhung cau ly thuyet thuong kha de, chi can chut it suy luan.
Ve cau truc de thi, phan nhieu cau hoi nhat la phan dao dong co hoc va phan dong dien xoay chieu. Phan dao dong co hoc thuong vuong o van de thoi gian di tu diem nay den diem kia. Tru mot so truong hop dac biet co the hoc thuoc, con lai nen chu y phuong phap giai tong quat dua vao moi lien he giua dao dong dieu hoa va chuyen dong tron deu. Voi phan dong dien xoay chieu, mot so cau hoi kho co the ve gian do va dung kien thuc hinh hoc don gian de giai.
Cac phan song anh sang, luong tu anh sang, hat nhan nguyen tu, tu vi mo den vi mo thuong cho ly thuyet kha nhieu nen can nam vung, hieu ro sau sac cac kien thuc trong sach giao khoa. Phan bai tap song anh sang thuong la giao thoa anh sang voi nhung kien thuc quen thuoc nhu tim so van, vi tri van trung…; phan bai tap hat nhan nguyen tu chu y den nang luong lien ket rieng, so hat nhan phan ra trong hien tuong phong xa, nang luong phan ung...
De phan phoi thoi gian lam bai hop ly, nen luu y cau truc de thi tot nghiep THPT gom hai phan: Phan chung (dao dong co: 6 cau; song co: 4 cau; dong dien xoay chieu: 7 cau; dao dong va song dien tu: 2 cau; song anh sang: 5 cau; luong tu anh sang: 3 cau; hat nhan nguyen tu va tu vi mo den vi mo: 5 cau); phan rieng: khoang 8 cau.
Thuoc long cong thuc
Thoi gian on tap khong con nhieu nen de chac chan dat 7 hoac 8 diem, cac em co the khong can dau tu nhieu vao chuong I va chuong VIII nhung chu trong cac noi dung sau day:
- Chuong II (dao dong co): Chu trong phan phuong trinh dao dong, phuong trinh van toc, phuong trinh gia toc. Cac khai niem dac trung (tan so, chu ky, bien do, pha dao dong, pha ban dau…); mo ta do thi ly do; cac bieu thuc dong nang, the nang, co nang; bieu dien dao dong dieu hoa va chuyen dong tron deu; dao dong tuan hoan; khao sat con lac lo xo nam ngang; dao dong tat dan, duy tri cuong buc, cong huong; tong hop dao dong dieu hoa; khao sat con lac don; do T va g.
- Chuong III (song co) va chuong IV (dao dong va song dien tu): Chu trong phan dai cuong ve song co; nhieu xa, phan xa, giao thoa, song dung; song am; cac dac trung cua song am; dao dong dien tu; dien tu truong.
- Chuong V (dong dien xoay chieu) va chuong VI (song anh sang): Chu trong cac khai niem ve dong dien xoay chieu; mach dien; cac may dien; khao sat mach RLC noi tiep; phan tan sac, nhieu xa, giao thoa; quang pho; tia hong ngoai, tu ngoai, Ron-ghen; do buoc song anh sang bang giao thoa; khe Y-ang.
- Chuong VII (luong tu anh sang): Luu y phan thi nghiem ve hien tuong quang dien; thuyet luong tu; dinh luat quang dien; luong tinh song hat; quang dien trong, quang dien ngoai; mau nguyen tu Bo; so luoc ve laze.
- Chuong IX (hat nhan nguyen tu) va chuong X (tu vi mo den vi mo): Chu trong phan cau tao, dong vi; khoi luong, nang luong nghi, lien ket, lien ket rieng; phan xa; phan ung hat nhan, phan hach, nhiet hach; luc hat nhan; hat so cap; he mat troi, sao va thien ha, cau tao vu tru.
Luu y la phai on that chac ly thuyet, thuoc long cac cong thuc de co the thao tac nhanh. Voi hoc sinh kha gioi, thoi gian lam gan hoan chinh mot de thi khoang 40 phut, 20 phut con lai danh cho cac cau con nghi ngo va 1 - 2 cau hoc bua.
| Lam truoc nhung cau chac dung Phan bai tap vi co nhieu ma de nen khong nhu thi tu luan la thuong cho cau de truoc, cau kho sau. Do do, cau nao lam nhanh, chac dung thi lam truoc, to luon tren dap an. Cac cau can tinh toan qua 2, 3 giai doan thi lam sau. Dung mat tinh than khi gap 2 hoac 3 cau dau tien kho. Toan vat ly thi can don vi, nhung neu nhin thay 4 dap an co so hang dau khac nhau va tinh toan chi co nhan chia (khong lay can hay luy thua) thi da so cac truong hop deu khong can doi don vi lam mat thi gio. Thi du: Neu chi tinh khoang van i = λ.D/a thi λ, D, a thuong la de se cho khac don vi nhung chung ta khong can doi don vi. |
