IIT JEE , AIEEE Forum - Physics , General - TARGET IIT-JEE 2008 || CHALLENGING PROBLEMS

Avinash_Bhat

HI FRIENDS,

I WOULD TRY MY BEST TO GET THE BEST QUESTIONS THAT ARE OF THE SAME STANDARD AS THAT OF THE PRESENT IIT-JEE LEVEL AND WE SHALL HAVE RELATED DISCUSSIONS ON THEM.

LET ME PUT DOWN THE FIRST CHALLENGER FROM MATHS(A SIMPLE ONE):

Avinash_Bhat

QN.1 Type : Only one of the options is correct.

The number of solutions of the equation : a^f(x) + g(x) = 0 ; where a is any natural number and g(x) = x² - x + 2 is:

(a) one
(b) zero
(c) infinitely many
(d) none of these

catchyash111

the answer is (c) . Isn't it???

Avinash_Bhat

SORRY! THERE IS A VERY SLIGHT MISTAKE IN THE QUESTION.

I HAVE FORMATED IT. NOW YOU MAY GO THROUGH IT.

THIS QUESTION IS TOO SIMPLE, MAY BE THE SIMPLEST ONE. I WILL COME UP WITH A BETTER ONE.

drish

r u sure that the ques is complete !

Avinash_Bhat

SORRY! THERE IS A VERY SLIGHT MISTAKE IN THE QUESTION.

I HAVE FORMATED IT. NOW YOU MAY GO THROUGH IT.

THIS QUESTION IS TOO SIMPLE, MAY BE THE SIMPLEST ONE. I WILL COME UP WITH A BETTER ONE.

sivaramakh

c right

Avinash_Bhat

FROM PHYSICS:

QN.2 Type: Only one of the options is correct. (Here vectors are represented by bold letters.)

A body of mass m is moving with velocity V₁ relative to an observer O₁ and with velocity V₂ relative to an observer O₂. Velocity of O₂ relative to O₁ is V₀. If E₁ and E₂ are kinetic energy of the body as measured by O₁ and O₂ respectively.

(a) E₂ = E₁ - ( m V₀² ) / 2 - m V₁.V₀(b) E₂ = E₁ + ( m V₀² ) / 2 - m V₁.V₀(c) E₂ = E₁ - ( m V₀²) / 2 - ( m V₁.V₀ ) / 2
(d) E₂ = E₁ + ( m V₀²) / 2 + ( m V₁.V₀ ) / 2

Avinash_Bhat

Hey SIVARAM, There was a slight mistake in the question and I had formatted it. Now.............. if your answer is to the present QN. 1; then it is not (c).

Avinash_Bhat

HEY FRIENDS,

PLEASE GIVE YOUR ANSWER WITH FULL SOLUTION SO THAT EVERY VIEWER UNDERSTANDS IT WELL........

harsha_27

The answer to the first question is
(B) Zero.

Soln.: discriminant of g(x) is -ve and coefficient of x^2 is +ve means g(x) is always +ve.

=> -g(x) is always -ve.

=> a^f(x) = -ve no.

as 'a' is a natural no. this equation cannot be true.

Hence there is no solution or Zero no. of solutions.

shweta1236

chetan_kp

for the first question the roots of the given equation represented by g(x) are imaginary while value of 'a' is natural , so for no value the equation is satisfied
hence zero solutions

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