1
GATE ME 2007
MCQ (Single Correct Answer)
+2
-0.6
Let $$X$$ and $$Y$$ be two independent random variables. Which one of the relations $$b/w$$ expectation $$(E),$$ variance $$\left( {{V_{ar}}} \right)$$ and covariance $$\left( {{C_{ov}}} \right)$$ given below is FALSE?
A
$$E\left( {XY} \right) = E\left( X \right)E\left( Y \right)$$
B
$${\mathop{\rm cov}} \left( {X,Y} \right) = 0$$
C
$$Var\left( {X + Y} \right) = Var\left( X \right) + Var\left( Y \right)$$
D
$$\,E\left( {{X^2}{Y^2}} \right) = {\left( {E\left( X \right)} \right)^2}\,{\left( {E\left( Y \right)} \right)^2}$$
2
GATE ME 2007
MCQ (Single Correct Answer)
+1
-0.3
The solution of $${{d\,y} \over {d\,x}} = {y^2}$$ with initial value $$y(0)=1$$ is bounded in the interval is
A
$$ - \infty \le x \le \propto $$
B
$$ - \infty \le x \le 1$$
C
$$x < 1,x > 1$$
D
$$ - 2 \le x \le 2$$
3
GATE ME 2007
MCQ (Single Correct Answer)
+1
-0.3
The partial differential equation $$\,\,{{{\partial ^2}\phi } \over {\partial {x^2}}} + {{{\partial ^2}\phi } \over {\partial {y^2}}} + {{\partial \phi } \over {\partial x}} + {{\partial \phi } \over {\partial y}} = 0\,\,\,\,$$ has
A
degree $$1$$ and order $$2$$
B
degree $$1$$ and order $$1$$
C
degree $$2$$ and order $$1$$
D
degree $$2$$ and order $$2$$
4
GATE ME 2007
MCQ (Single Correct Answer)
+2
-0.6
If $$\phi (x,y)$$ and $$\psi (x,y)$$ are function with continuous 2nd derivatives then $$\phi (x,y)\, + \,i\psi (x,y)$$ can be expressed as an analytic function of x +iy ($$i = \sqrt { - 1} $$) when
A
$${{\partial \phi } \over {\partial x}} = - {{\partial \psi } \over {\partial x}},\,{{\partial \phi } \over {\partial y}} = {{\partial \psi } \over {\partial y}}$$
B
$${{\partial \phi } \over {\partial y}} = - {{\partial \psi } \over {\partial x}},\,{{\partial \phi } \over {\partial x}} = {{\partial \psi } \over {\partial y}}$$
C
$${{{\partial ^2}\phi } \over {\partial {x^2}}} + {{{\partial ^2}\phi } \over {\partial {y^2}}} = {{{\partial ^2}\psi } \over {\partial {x^2}}} + {{{\partial ^2}\psi } \over {\partial {y^2}}} = 1$$
D
$${{\partial \phi } \over {\partial x}} + {{\partial \phi } \over {\partial y}} = {{\partial \psi } \over {\partial x}} + {{\partial \psi } \over {\partial y}} = 0$$
EXAM MAP
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
CBSE
Class 12