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Catalogs Discussion Forums -> Electricity -> Capacitance -> Go to message
This Post 2 points    (Olaaa!! Perrrfect answer.   in 1 votes )   [?]
for aparallel plate capacitor, capacitance is inversely proportional to d, hence it will decrease.
the variation of potential depends on whether the capacitor is connected in a circuit or isolated.
If connected in a circuit, the potential remains constant(charge varies)
if isolated, charge remains constant, hence potentail increases.
Catalogs Discussion Forums -> Electricity -> transmission of electricity -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
r is costt.
when v will be high, i will also be high???
Catalogs Discussion Forums -> Algebra -> minimum value.. -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
I can get this far
let x^(lny)=a
x^)lnz)=b
y^l(lnz)=c

then the given expression reduces to : a/b + a/c + b/c
Catalogs Discussion Forums -> Electricity -> transmission of electricity -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
Why is electricity from power plants is transmitted at high potential difference???
Power is v*v/r, it will increase????
Catalogs Discussion Forums -> Mechanics -> this question remains unanwered -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
y1=8sin(omega*t)
y2=6cos(omega*t)
y3=-4sin(omega*t)
y4=-2cos(omega*t)

y=y1+y2+y3+y4=4(sin(omega*t)+cos(omega*t))

hence
amplitude:4*square root of 2
phase:pi/4
Catalogs Discussion Forums -> Physical Chemistry -> electronegativity -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
the rule is that if there is a diffference of 1.7, then the molecule possess 50% ionic character(for 100%, electronegativity difference-->infinity)

1.4 difference means that more covalent than ionic
Catalogs Discussion Forums -> Optics -> refraction through plane surface -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
Just one small question:
It is said that light coming from fish's eye at an angle greater tan critical angle suffers TIR at the surface of water and hence fish has limited vision. Right.

But, a creature,s vision depends on the light entering. If light is entering from air, how can it suffer TIR??
Catalogs Discussion Forums -> General Physics -> How Can This Be True? -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
I know its soution :
Observe the hypotenuse of the original triangle.It seems straight, but it s not.
Calculate the slope of hypotenuse of green triangle and red triangle, they are different indicating that hypotenuse of the original triangle is not straight line.
Catalogs Discussion Forums -> Optics -> once more.. -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
I don't know about the method, but the concept is given in our syllabus
Catalogs Discussion Forums -> Electricity -> question on charge and potential energy -> Go to message
This Post 2 points    (Olaaa!! Perrrfect answer.   in 1 votes )   [?]
nikhil
I have something for you.

first notation, since I can't use usual notations due to inability

a: mass of electron
b:mass of proton
e:charge of proton
r:the required distance
v:initial velocity of electron
w:final velocity of proton

the question is one dimensional interaction between proton and electron. The system consists of electeon and proton, and they attract each other through conservative electric field(magnetic effects are neglected).

Applying law of consevation of momentum
av=a*2v-b*w
(if electron is moving initiallly in positive x-direction, then finally it will be moving in +x and proton in -x due to mutual attraction)

Aplplying law of conservation of energy
a*v*v/2=a*2v*2v/2+b*w*w/2-eV(r)

Using, these two equations, you can find r

if you find w from first equation and substitute in second equation, you observe that kinetic energy of proton involves square of a/b, which is very small and hence can be neglected.
Catalogs Discussion Forums -> Algebra -> Can anyone solve these?? -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
in the equation, I hope that the sides of triangle are joining the non-adjacent vertices of the triangle

three vertices of a triangle can be chosen in C(n,3) ways.
three vertices are chosen that they are three consecutive sides: n
three vertices chosen so that two of them are adjacent:(n-4)*C(n,1)
the required no. of ways=C(n,3)-n-(n-4)*C(n,1)
Catalogs Discussion Forums -> Analytical Geometry -> HOW TO PROVE ? -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
can you just give me the equation of the tangents from the point(x,y) to the circle of radius r with centre at (0,0)
Catalogs Discussion Forums -> Trignometry -> i made the question clear[Admin]: Range of an angle in a triangle -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
here is how I got the range

let D be the mid-point of BC
let AM be the altitude of triangle
let 'd' be the distance between O(circumcentre) and H(orthocentre)
let 2a be the length of BC
consider triangle BDO, find DO in terms of a and A
DO=atanA.........................(1)
consider triangle BMH, find MH in terms of a,d and C
MH=(a-d)tanC.........................(2)
consider triangle CMH, find MH in terms of a,d and B
MH=(a-d)tanB.........................(3)

since OH is parallel to BC
DO=MH
equate 1 and 2 find a/d
equade 1 and 3 find a/d
equate a/d found in above two steps
we will get a equation in tanA, tanB and tanC

now you can find the range using the following :
A+B+C=pi
B not equal to C(scalene) hence tanB not equal to tanC
tanB and tanC, both are greater than zero(acute triangle)
Catalogs Discussion Forums -> Mechanics -> Help I need to verify the answer to this question!!!!!!!!!! -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
Although I have solved it myself, follow this link
star.tau.ac.il/QUIZ/05/hrsol.pdf
Catalogs Discussion Forums -> Electricity -> Resistance of heater wire -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
heater has a high restance so that a large amount of electric power is dissipated as heat energy, which we use
Catalogs Discussion Forums -> Modern Physics -> photoelectric effect (tough one) -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
picture is not working in last post
he general equation of a wave is
Asin(omega*t-theta)
omega=2pi/T=2pi*c/lambda
theta=x/lambda
Catalogs Discussion Forums -> Modern Physics -> photoelectric effect (tough one) -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
the general equation of a wave is
Asin(t-)
now concerntrate on the angle term
=2pi/T=2pi*c/lambda

=x/lambda
Catalogs Discussion Forums -> Differential Calculus -> pt 1=2 -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
there is a proof for 1=2

ln2 = 1 -1/2 + 1/3 - 1/4 +....
ln2= (1+1/3+1/5+..)-(1/2+1/4+1/6+..)
adding and subtractng the last term
ln2= (1+1/3+1/5+..)-(1/2+1/4+1/6+..)+(1/2+1/4+1/6+..)-(1/2+1/4+1/6+..)
ln2= (1+1/3+1/5+..)-(1/2+1/4+1/6+..)-(1/2+1/4+1/6+..)+(1/2+1/4+1/6+..)
ln2= (1+1/3+1/5+..)-2(1/2+1/4+1/6+..)+(1/2+1/4+1/6+..)
ln2=(1+1/2+1/3+1/4+..)-(1+1/2+1/3+1/4+..)
ln2=0
2=1
Catalogs Discussion Forums -> Trignometry -> solving trignometric inequalities graphically -> Go to message
This Post 2 points    (Olaaa!! Perrrfect answer.   in 1 votes )   [?]
yes, itmeans you imagine a graph or better draw a graph.
sippose the question is
sinx greater than or equal to 1/2

graph sinx
draw line y=1/2
you will see that if x is greater than pi/3 and less than 2pi/3 the condition is satisfied.
to generealise it, add 2npi
Catalogs Discussion Forums -> Analytical Geometry -> HOW TO PROVE ? -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
this is a hint
Let PA touches C1 at M
then M is the mid-point of PA
 
 
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