Category Archives: IIT JEE

$x^2-x-1=0$

$R(x)=\frac{{{x^{16}} – 1}}{{{x^8} + 2{x^7}}} = ?$

$R(x)=\frac{{{x^{16}} – 1}}{{{x^8} + 2{x^7}}} = \frac{{({x^2} – 1)({x^2} + 1)({x^4} + 1)({x^8} + 1)}}{{{x^7}(x + 2)}}$

$\because {x^2} – x – 1 = 0,{x^2} – 1 = x$

$R(x) = \frac{{x({x^2} + 1)({x^4} + 1)({x^8} + 1)}}{{{x^7}(x + 2)}} = \frac{{({x^2} + 1)({x^4} + 1)({x^8} + 1)}}{{{x^6}(x + 2)}}$

$\because {x^2} – x – 1 = 0,{x^2} = x + 1$ Continue reading $x^2-x-1=0$

$R(x)=\frac{{{x^{16}} – 1}}{{{x^8} + 2{x^7}}} = ?$

A capacitor of capacitance ‘C’, is connected ….

A capacitor of capacitance ‘C’, is connected across an AC source of voltage V, given by $V=V_0 sin \omega t $. The displacement current between the plates of the capacitor, would then be given by:

(1) $I_d = V_0 \omega C cos \omega t $
(2) $I_d = \frac {V_0}{\omega C} cos \omega t $
(3) $I_d = \frac {V_0}{\omega C} sin \omega t$
(4) $I_d = V_0 \omega C sin \omega t $ Continue reading A capacitor of capacitance ‘C’, is connected ….

The pressure acting on a submarine is $3 \times 10^5 Pa $ ….

The pressure acting on a submarine is $3 \times 10^5 Pa $ at a certain depth. If the depth is doubled, the percentage increase in the pressure acting on the submarine would be:

(Assume that atmospheric pressure is $1 \times 10^5 Pa$, density of water is $10^3 kgm^{-3}$, $g=10 ms^{-2}$)

(A) $\frac {3}{200} $%
(B) $\frac {5}{200} $%
(C) $\frac {200}{3} $%
(D) $\frac {200}{5} $% Continue reading The pressure acting on a submarine is $3 \times 10^5 Pa $ ….