Doubts from JEE PYQs

say for example tumhe room temp 20 diya hai and initial final 29/27
error is more when interval is far from 20 degree celsius

1 Like

Heat conduction kal se shuru hua ab thore din me hojayaga

1 Like

Isme log use karna hh @Gauri

1 Like

Matlab inital and final temp close to room temp hone chahiye aisa and Ti,Tf me gap kam hona chahiye tab average?

Aight! Thanks @Dexter27 @Gauri @Deadpool :slight_smile:

4 Likes

yes

3 Likes

D2 D1 D4 D3_1

First ne blackhole kyu nahi? Perfect black body?

Baki 2nd ka concept bata do.

3rd and 4th me solution hi golmol diye hh

1 Like

Shi to given h approximately 0.002kJ hi arha h actually me 0.0019968kJ ke aas pass

2 Likes

Ismein bhi approximately closest value 0.5 kcal/kg or 0.5cal/g maan skte h actual 0.61cal/g k aas pass h

Ye sb purane mains k saval h na… Us time bhott chlta tha approximations n all… Aaj kal to avogadro number ko bhi 6.022x10^23 pura hi lekr chalne me bhalayi h(unless stated, otherwise) :joy:

3 Likes

1st k liye mere pass koi explanation nhi h :weary::neutral_face:

3 Likes

2nd vala kr to dunga but proper feeling nhi aa payegi question ki :sweat_smile: u know jugaads… Isliye uske liye concept master @VictoryGod or @Strange_Wizard h

4 Likes

Stack exchange check kiya maine usme likha hai ki koi unruh effect hota hh jiski vajah se black hole perfect black body hoti hh :sweat_smile::sweat_smile::sweat_smile::sweat_smile:

2 Likes

Lets not go beyond syllabus :sweat_smile: vse question hi galat krdo fir to… Kyunki abhi poori theory available hui kha h black hole ki… Hr var kuch na kuch mysterious nikal ata h… To ye log question me kaise dal skte h :sweat_smile:… Kya pta 2050 me balck body prove ho jaye fully… Fir to uss sal ke jee aspirants :sweat_smile: galat answer kehnge

3 Likes

Black hole emits radiation as well as absorbs it. So, it is not considered as Black Body.

4 Likes

@Lavesh
Second wale me energy conservation hai
Pehle bubble ka radius R aur temperature T assume kro
Ab jab heat denge to water evaporate hoga??
Aur evaporation surface phenomenon hai to
∆r kam kardo final bubble me se to radius bachega
R-∆r. Aur temperature constant whi T

Ab Energy hogi
Y∆A (surface area)
Aur ML
Ab mass ayega Density Se jo change in volume ko multiply karoge Density se to Mass evaporated ayega
Is mass ko ML me rakhdo
Aur energy equate kro Y∆A = ML
I hope answer aa jaye shayad :sweat_smile::pray:

6 Likes

first mee to emmisivity compare krna h
black body ka e =1
aur paint ka bhi sbse jyada e h
given options me
info based question
(black hole are not objects bs confuse krne k liye diya h)
jitna dark colour utna jyada e

5 Likes

Temperature kisme liya hh Celsius me. And kisme lena hh? Kelvin me.

1 Like

Blackbodies also emit radiation as well as absorb it. Infact everybody does so. IG you mistyped something here.

2 Likes

Try karta hu iss se hojaye toh.

Thanks @Dexter27 @Deadpool @VasuBro @VictoryGod

3 Likes

Yeah Sorry bro.
I typed this. :man_facepalming:

1 Like

Black hole aren’t objects :relieved: (type of vaccume created in space IG)

3 Likes