Physics, Chemistry, Mathematics Forums

If the soution set of sin^-1(3x-4x³)=3sin^-1x is A and the solution set of            cos^-1{2x(1-x²)^1/2}=2sin^-1x is B then  \(A \cap B\)

CH₃COCH₃  LAH  ₎ ()  H⁺/Br₂+CCl₄___₎₍₎NaNH₂liq NH₃ _₎₍₎ Na liq NH₃____)X

_{X IS :}

 

A) Trans CH₃CHCHCH₃

B) Cis CH₃CHCHCH₃

C) CH₃CCH

D) CH₃CCNa

A car moves with a constant tangential acc. A(t)=2/3 m/s² along a horizontal surface  circumscribing a circle of radius r = 40 m. The coefficient of sliding friction between the wheels of car and the surface is u_s = 0.20 . What distance will the car ride without sliding if at the initial moment  of time its velocity is equal to zero? Take g = 10  m/s²

What is the electric field due to a uniformly charged circular disc at a distance d from centre in the plane of disc?

In H.C. Verma book, the statement of ampere's law says line integral of vector B.dl=(mu not)I(inside),provided that electric field is constant. Why electric has to be constant and if it is not constant then what happens? 

Q.1}If r>p>q,the number of differnt selections of p+q things taking r at a time,wheer p things are identical and other q things are identical, is

[a] p+q-r   [b] p=q-r=1   [c] r-p-q+1    [d] none of these 

Q.2}A bag contains 3 black,4 white and 2 red balls,all the balls being different.The number of selections of at most 6 balls containing balls of the colours is

[a] 42*{4}! [b]2⁶*{4}!  [c] (2⁶-1){4}!  [d] none of these

The given assembly made of conducting wire is rotated with a constant angular velocity w about a real axis AC as shown in figure. AD part of assembly is quarter circle of radius R and DB is straight and parallel to axis AC. The magnetic field B’ exists vertically upward parallel to axis AC .Find the potential difference between points A and B(only the magnitude).Options are <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

 

(A)    B’(w R²  /2)

(B)    B’(w∏ R²  /4)

(C)    B’ w (2 R²  − ∏ R²  /4)

(D)    zero

 

Find the electric field at the centre of a hemispherical surface of surface charge density € using gauss law?

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Three identical parallel conducting plates A, B and C are placed as shown. Switches S1 and S2 are open, and can connect A and C to earth when closed. +Q charge is given to B. Then which of the following options is/are correct?

(A)   If S1 is closed with S2 open, a charge of amount Q will pass through S1.

(B)   If S2 is closed with S1 open, a charge of amount Q will pass through S2.

(C)   If S1 and S2 are closed together, a charge of amount Q/3 will pass through S1, and a charge of amount 2Q/3 will pass through S2.

(D)   All the above statements are incorrect.       

How many natural numbers not exceeding 4321 can be formed with the digits 1,2,3 and 4 ,if the digits can repeat?  Answer is 313.