IIT JEE Challenge 2.0 ( Entry Open )

This challenged is designed for staying you in the track of IIT JEE or NEET or Any other UG Exam Preparation. It will also motivate you. I will post 2 to 5 Math & Chemistry Quiz(MCQs) Daily.

Anyone can join



Question - 1

2 + 1 + ½ + ¼ + ⅛ + …….∞ = ?

a. 8

b. 4

c. 6

d. None of these

Question - 2

The length of the tangent drawn from the point (4,-1) to the circle 2x² + 2y² = 1 is

a. √22 unit

b. √33 unit

c. √99 unit

d. √31 unit

Question -1:
Ans: b. 4

Hint: Sum of infinitely decreasing G.P = a/(1-r)

Here a=2 and r=1/2

1 Like

Question 2.

I think all options are wrong, since the radius of the circle is 1/√2. So the answer must contain 1/√2.

Correct answer:
√{(4^2 + (-1)^2) - 1/2} = √(33/2)

1 Like

@Amitroghates physics instead of maths please? Being from PCB sucks :sweat_smile::joy:


What? I mean if you say physics sucks, I would agree :joy: but the whole PCB, I don’t think so :joy:.


Nah don’t take it otherwise :joy: i love PCB… what i was saying is that here only maths and chem mcqs are being posted… So in that way Biology Stream isn’t getting a fair chance… That’s what i was saying


@BlackMagic123 btw this reminded me of a mnemonic… Morphology of flowering plants… Pineapple, Chrysanthemum and Banana (PCB) are the examples of suckers (sucks) :joy:


Nice mnemonics…

Please tell me some of your mnemonics

1 Like

1 Like

Is 2 the right answer ?


I think 3… Inductive effect


Alright I’ll share some when they’ll occur to me

1 Like

Z = re(z) + im(z) is a complex number where re(z) is plotted along or parallel to x-axis and im(z) is plotted along or parallel to y-axis.
For example, If Z = a + ib , then a is plotted as ordinated and b is plotted as abscissa.

Arg(z) is

a. arctan(im(z)/re(z))

b. tan^-1(re(z)/im(z))

c. arcsin(re(z)/im(z))

d. cos^-1(re(z)/im(z))

Answer 3 is correct. Inductive effect.

+I effect destabilises anion as CH2CH3 is an EDG.

+I effect is more in ortho substituted species in benzene rings since it is at less distance from the negative charge.

1 Like

Correct answer brother


Actually I didn’t read the question properly and jumped to conclusion and told the most stable one.

1 Like