Physics, Chemistry, Mathematics Forums

 An object and a screen are fixed at a distance d apart.When a lens of focal length f is moved between the object and the screen ,sharp images of the object are formed on the screen for two positions of the lens.The magnifications produced at these two positions at these two positions are M₁ and M₂.[a] d>2f [b] d>4f [c] M₁M₂=1 [d] |M₁ |  -  |M₂  | =1. Since sharp images are formed then all the rays should come and focus on the same place.So,object should be placed at a very far off distance.So,option [b] should be correct.But answers are [b] and [c].Somebody please explain other options.

The area bounded by y=mod(x-1) and y=1 is :

a)1                b)2              c)1/2             d)none of these

Ans. given is a.

 
PLEASE GIVE ME THE STEPS

A cart of total mass M is at rest on a rough horizontal road. It ejects bullets at a

 rate of   \(\lambda\frac{kg}{s}\)   at an angle  \(\theta\)  with the horizontal

 and at a velocity u(constant) relative to the cart. The coefficient of friction

 between the cart and the ground is  \(\mu\) . Find the velocity of the cart as

 a function of t. The cart moves with sliding.


THE ANSWER IS

what is the value of

\(\sum\limits^{\infty}_{1}\tan^{-1}(1/r^4)\)

 

H2(g) and Cl2(g) are Kept in separate vessels of volume "V" at pressure "P" and temperature "T" each. If suddenly pressure on both vessels are doubled, which gas will occupy a greater volume.

A unit cell has A2+ ions at all the corners and body centre of the cube. Then a possible arrangement of anions

A. B- at all face centres
B. B2- at all face centres
C. B- at four face centres and B2- at two face centres
D. B2- at four face centres and B- at two face centres
E. B3- at four face centres

P.2 : COMPOUND A2B3 HAS A DEFECTED STRUCTURE HAVING THE FORMULA A2B2.85. THEN HOW MANY LATTICE SITES PER MOLE IN THE CRYSTAL REMAINS VACANT?

plz solve it for me....!!!!

Urgent :- NCERT Electrochemistry Diagram Confusion

Let {D1,D2,......,Dk} be the set of third order determinants that can be made with the distinct nonzero real numbers a1,a2,a3.....,a9,then

(a)k=factorial 9    (b) D1+D2+........+Dk=0    (c)at least one Di=0  (d) none of these.