Physics, Chemistry, Mathematics Forums

When a coil carrying steady current is short-circuited,the current becomes 1/n times initial current in time to.The time constant of the circuit is?

Ans:to/ln n

My Doubt:Steady current initially==> a DC source must be present, lets say cell of emf E.Resistance is ofcourse present.Now only inductor is shorted.So here we can't use the concept of decay of current wherein we assume that E is removed suddenly and we see the nature of i.Here E is not removed.But still the ans comes only by using this concept wherin we develop i=i_oe^-(R/L)t.PLz reply

Please solve the following integral:
Undetermined error: @@lim(int((kx-box{kx})^k dx,0,kbox{x}),k,infty)@@ ; k belongs to N (where box(.) denotes grestest integer function)

NOTE:- Please consider box(.) as [.] for convenience. Since the system wasn't accepting [.] symbol, I wrote it as box(.)

(a) box(kx) (b) box(x) (c) box(Undetermined error: @@x/k@@) (d) box(Undetermined error: @@x^k@@)

The ans. is given as b. Please reply.

A narrow tube of radius r and length l is protruding from a cylindrical tank at a height h from it's base. the area of base is A(>>>pie*r^2). The tank is fixed horizontally. A liquid wih coefft of viscosity neta is filed to height H.

for max range of liquid on the horizontal surface, the value of h is?

a) 2H/3
b) H/3
c) H
d) H/2

The determinant \(\Delta\) = \(\left|{\matrix{d^2+r & de & df\cr de & e^2+r & ef\cr df & ef & f^2+r\cr}}\right|\) is divisible by:

(a) Undetermined error: @@r^2@@ (b) Undetermined error: @@d + e^2 + f^2 + r@@ (c) Undetermined error: @@d^2 + e^2 + f^2 + r@@
(d) Undetermined error: @@d^2 + e + f^2 + r^2@@

I don't know the ans. Please reply.

a 3.6m long pipe isfilled completely with a liquid. as mall hole is drilled at the base of the pipe due to which liquid starts leaking. this pipe resonates with a tuning fork at water column heights 3.22m and 2.34 m. the area of cross-section of pipe is?

Please solve the following integral
\(\int{(dx/sqrt(cos^3 x cos(x-a))}\) is equal to

(a) 2Undetermined error: @@sqrt(tanx sina + cota)@@ + c
(b) 2cosecaUndetermined error: @@sqrt(tanx sina + cosa)@@ + c
(c) 2Undetermined error: @@sqrt(sina + tanx cosa)@@ + c
(d) 2cosecaUndetermined error: @@sqrt(tanx cosa + sina)@@ + c

The ans. is given as b, Please try this and reply.

what is the value of rydberg constant?

a) 109,677 cm^-1

b) 1.09677X10⁷ m^-1

c) 2.18X10^-18 J

d) 3.29X10¹⁵ Hz

How many holes are present at h/4 distance in HCP unit cell structure?
(here h = height of unit cell)
(a) 3 (b) 4 (c) 2 (d) 1
The ans. is given as option a. Please reply soon with explanation.

Why are (alpha)-amino acids neutral.Books say that it is because it has basic(NH₂) as well as acidic group(-COOH).

I think it should be termed as acid as well as basic because definition of acid(/basic) just says acceptance(/donation) of electrons which are both satisfied simultaneously by them.

CAN SOMEBODY EXPLAIN THE GEOMETERY OF [Ni(CN)₄]^-2 AND [Ni(Cl₄)]^-2?