goIIT: IIT JEE AIEEE CET WBJEE VITJEE BITSAT IIIT AICET Engineering Entrance Experts, Student Discussion Community, IIT JEE Preparation Online

hey administrator ,

i have registered for the test and was going to give the test today but it is displaying only this much

	Presents
	HEADSTART - AIEEE 2007

Started at: Wed Apr 25 10:01:59 UTC+0530 2007
Time Left: 180 minutes

Page 1

Instructions

There are three sections in this paper consisting of Physics, Chemistry & Mathematics having 40 questions each.

For each correct answer 3 marks will be awarded and for each incorrect answer, 1 mark will be deducted.

The duration of exam is 3 Hours.

Mark only one correct answer out of four alternatives.

Please do not use calculators or books during the test, for genuine analysis.

page 2,3,4 none of them are working.

even some of my friends faced the same problem. time is running out,

so what should be done?

i m getting confused here.

please reply as early as possible.

(even my intenet explorer version is 6)

b4 collision

for neutron,

= h/mv = 3.9677 X 10^-7 / v metres

for dueterium,

= h/mv = infinity ( as v = 0 )

after collision

take collision to be perfectly elastic

Vn = 0 , Vd = v/2

for neutron,

= infinity

for deuterium,

= 3.9677 X 10^-7 / v metres

PS:pls rate me for if i m correct

b and c are correct

look, as a dielectric slab is placed b/w the plates of the capacitor, its capacitance increase. Now, Q = CV

if C increase, V decrease.

But the direction of electric field remain same.

this is because of presence of unpaired electrons in valance sell of the transition elements.

always at ur service

Nice question yaar

the energy of electron in first shell of H-atom = 13.6 eV

or (1/2)mv² = 2.178 X 10^-18 J

or v² = (2 X 2.178 X 10^-18 )/(9.1 X 10^-31)

v² = 4.787 X 10¹²

v = 2.188 X 10⁶m/s

Now if it is true that the electrostatic force of attraction between the nucleus and electron provides the centripetal force to the electron for revolving around the nucleus, then

ke²/r² = mv²/r

r = Bohr?s radius = 0.529 X 10^-10 m

or ke²/r = mv²

v² = ke²/mr

= (9 X 10⁹)(1.6 X 10^-19)²/ (9.1 X 10^-31)(5.29 X 10^-11)

= 4.786 X 10¹²

v = 2.187 X 10⁶ m/s

Thus, , velocity of electron in first orbit of H atom comes out to be the same from both the experiments. Hence proved that the electrostatic force of attraction between the nucleus and electron provides the centripetal force to the electron for revolving around the nucleus.

Cheers!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Confirm the diagram please

sorry, but you are wrong sabnisneil

elastance = 1/capacitance = 1/Farad

= Farad^-1

REQUEST: PLEASE DONT KILL ME IF I AM WRONG

'V' on B = V_B + V_C

= k[ (4 X 10^-6)/0.2 + (3 X 10^-6)/0.3 ]

= (9 X 10⁹ ) (3 X 10^-7)

= 2700 volts

U_total = U_A + U_B + U_C

= (1/2)q_AV_A + (1/2)q_BV_B + (1/2)q_CV_C

=(1/2)(0)(V_A) + (1/2)(4 X 10^-6)(2700) + (1/2)(3 X 10^-6)(V_C)

Now, V_C = kq_B/r_C + kq_C/r_C

= k[(4 X 10^-6)/0.3 + (3 X 10^-6)/0.3]

= 2100 volts

U_total = (1/2)(4 X 10^-6)(2700) + (1/2)(3 X 10^-6)(2100)

= 8.55 X 10^-3 J

it is reciprocal of capacitance.

S.I. units of elastance are Farad^-1

are r some tricks whi are told at coachings and most of them can be found in any good book. but if u practice each and every type of questions , you can also find some simple tricks by yourself. so, don't get depressed

THANKS A LOT FOR THE INFORMATION, RAJAT.

i will pass it to my friends also.

HEY WATCH OUT !

!!!!!!!!!!!!!!!!!!!!!!!! I AM HERE !!!!!!!!!!!!!!!!!!!!!!!

WISH U A VERY VERY VERY Happy birthday, Sir

i hope that not only todays but everyday turns out to be as awesome for u

go for ARIHANT

HEADSTART - AIEEE 2007

Page 1

Instructions