O’zbekistоn respublikasi оliy va O’rta maxsus ta`lim vazirligi

Transformatorlar.
1. Kuchlanishni U₁=120 V dan U₂=480 Vga kuchaytiradigan transformatorning birlamchi chulg’amdagi o’ramlar soni N₁=800 bo’lsa, transformatsiyalash koeffitsiyentini va ikkilamchi chulg’amdagi o’ramlar sonini toping.
2. Kuchaytiruvchi transformatorning birlamchi chulg’amda N₁=125 o’ram, ikkilamchi chulg’amida esa N₂=2000 o’ram bor. Birlamchi chulg’amning uchlaridagi kuchlanish u₁=220 V, ikkilamchi chulg’amdagi tokning kuchi I₂=0,5 A bo’lsa, transformatorning foydali quvvatini toping.
3. Pasaytiruvchi transformatorning ikkilamchi chulg’ami zanjirdagi kuchlanish U₂=110 V va tokning kuchi I₂= 4 A bo’lganda, kuchlanishi U₁=220 V bo’lgan birlamchi chulg’amdagi tokning kuchini toping. Energiya isrofini hisobga olmang.
4. Transformatsiyalash koeffitsiyenti k = 40 bo’lgan transformator U₁=220 V kuchlanishli tarmoqqa ulangan. Ikkilamchi chulg’amga R=11 Om qarshilikli asbob ulangan bo’lsa, asbobdan o’tayotgan tokning kuchini toping.
5. Transformatsiyalash koeffitsiyenti k = 20 bo’lgan pasaytiruvchi transformator U₁=220 V kuchlanishli tarmoqqa ulangan. Agar transformatorning ikkilamchi chulg’amining qarshiligi R=0,4 Om bo’lib, aktiv nagruzkaning qarshiligi R= 4 Om bo’lsa, transformatorning ikkilamchi chulg’am uchlaridagi kuchlanishni toping.
6. Transformatorning birlamchi chulg’amidagi tokning kuchi I₁= 5 A, uning uchlaridagi kuchlanish U₁=120 V ikkilamchi chulg’amda tokning kuchi I₂= 2 A, kuchlanish esa U₂=285 V bo’lsa, transformatorning cosφ=1 bo’gandagi FIK ni toping.
7. Radiopryomnikning tok kuchi transformatorlaridagi birlamchi chulg’am N₁=11000 o’ramdan iborat bo’lib, u U₁=220 V kuchlanishli tarmoqqa ulangan. Agar ikkilamchi chulg’amning qarshiligi R₂=0,5 Om va uning kuchlaridagi chug’lantirish kuchlanishi tok kuchi I₂=1 A bo’lganda U₂=6,5 V bo’lsa, ikkilamchi chulg’amdagi o’ramlar sonini toping.
8. Pasaytiruvchi transformatorning birlamchi chulg’ami U₁=220 V kuchlanishli tarmoqqa ulangan. Transformatorning ikkilamchi chulg’ami uchlaridagi EYUK E₂=9 V, chulg’amning qarshiligi R₂=1 Om, undan o’tuvchi tok I₂=2 A bo’lsa, transformatorning transformatsiyalash koeffitsiyent k va FIK ni toping. Birlamchi chulg’amdagi energiyaning isrofini hisobga olmang.
9. Transformatorning birlamchi chulg’ami U₁=220 V kuchlanishli tarmoqqa ulanib, u salt ishlaganda, uning ikkilamchi chulg’amda U₂=60 V kuchlanish hosil bo’ldi. Birlamchi chulg’amdagi o’ramlar soni N₁=660. Agar transformatorning FIK η=90% bo’lsa, ikkilamchi chulg’amdagi o’ramlar sonini toping.
10. Transformatsiyalash koeffitsiyenti k =11 bo’lgan transformator U₁=220 V kuchlanishli tarmoqqa ulangan. Ikkilamchi chulg’amning qarshiligi R₂=1,2 Om, undagi tok esa I₂= 5 A bo’lsa, ikkilamchi chulg’amga ulangan aktiv nagruzkaning qarshiligini va ikkilamchi chulg’am uchlaridagi kuchlanishni toping.