Mathematical Physics Quiz for JAM, JEST, CUET PG, CPET & other MSc Physics Entrance Exams. Please wait... 1. The function $e^{\cos x}$ is Taylor expanded about $x=0$. The coefficient of $x^2$ is$-\frac{1}{2}$$-\frac{e}{2}$$\frac{e}{2}$$0$ 2. Let M be a $2\times 2$ matrix. Its trace is 6 and its determinant has value 8. Its eigenvalues are2 and 43 and 32 and 6-2 and -3 3. The solution $y(x)$ of the differential equation $y\frac{dy}{dx}+3x=0$, $y(1)=0$ is described byan ellipsea circlea parabolaa straight line 4. The volume integral $\int_V e^{-(r/R)^2}\vec{\nabla}\cdot(\frac{\hat{r}}{r^2})d^3 r$, where $V$ is the volume of a sphere of radius $R$ centered at the origin, is equal to$4\pi$$0$$8\pi$$\frac{4}{3}\pi R^3$ 5. If $P$ and $Q$ are ermitian matrices, which of the following is/are true?A. $PQ+QP$ is always Hermitian.B. $i(PQ-QP)$ is always Hermitian.C. $PQ$ is always Hermitian.D. $PQ-QP$ is always Hermitian.Choose the correct answer from the options given below:A, BC, DA, DB, C 6. The line integral of the vector function $\vec{A}(x,y)=2y\hat{i}+x\hat{j}$ along the straight line from (0, 0) to (2, 4) is12642 7. The function $f(x)=\frac{8x}{x^2+9}$ is continuous everywhere except at$x=0$$x=\pm 9$$x=\pm 9i$$x=\pm 3i$ 8. If $\phi(x,y,z)$ is a scalar function which satisfies the Laplace equation, then the gradient of $\phi$ issolenoidal and irrotationalsolenoidal but not irrotationalirrotational but not solenoidalneither solenoidal nor irrotational 9. The eigenvalues of $\begin{pmatrix}3 & i & 0\\-i & 3 & 0\\0 & 0 & 6\end{pmatrix}$ are2, 4 and 62$i$, 4$i$ and 62$i$, 4 and 80, 4 and 8 10. The gradient of a scalar field $S(x,y,z)$ has the following characteristic(s).A. Line integral of the gradient is path independent.B. Closed line integral of the gradient is zero.C. Gradient is a measure of the maximum rate of change.D. Gradiet is scalar quantity.Choose the most appropriate answer from the options given below:A, B, CC, DA, DB, D 11. Let $f(x,y)=x^3-2y^3$. The curve along which $\vec{\nabla}^2f=0$ is$x=\sqrt{2}y$$x=2y$$x=\sqrt{6}y$$x=-y/2$ 12. A curve is given by $\vec{r}(t)=t\hat{i}+t^2\hat{j}+t^3\hat{k}$. The unit vector of the tangent to the curve at $t=1$ is$\frac{\hat{i}+\hat{j}+\hat{k}}{\sqrt{3}}$$\frac{\hat{i}+\hat{j}+2\hat{k}}{\sqrt{6}}$$\frac{\hat{i}+2\hat{j}+2\hat{k}}{3}$$\frac{\hat{i}+2\hat{j}+3\hat{k}}{\sqrt{14}}$ 13. The function $f(x)=\left\{\begin{matrix}x, -\pi<x<0& \\-x, 0<x<\pi\end{matrix}\right.$ is expanded as a Fourier series of the form $a_0 + \sum_{n=1}^{\infty}a_n \cos(nx)+ \sum_{n=1}^{\infty}b_n \sin(nx)$. Which of the following is true?$a_0 \neq 0, b_n=0$$a_0 \neq 0, b_n \neq 0$$a_0 = 0, b_n=0$$a_0 = 0, b_n \neq 0$ 14. Let $f(x)=3x^6-2x^2-8$. Which of the following statements are true?A. The sum of all its roots is zero.B. The product of its roots is $-\frac{8}{3}$.C. The sum of all its roots is $\frac{2}{3}$.D. Complex roots are conjugates of each other.A, B, DA, C, DC, DB, C 15. For the Fourier series of the following function of period $2\pi$,$f(x)=\left\{\begin{matrix} 0, -\pi<x<0,& \\1, 0<x<\pi\end{matrix}\right.$, the ratio of the Fourier coefficients of the first and the third harmonic is:1236 16. If $\lambda$ is an eigen value of a non-singular matrix $A$, then the eigen value of $A^{-1}$ is$-\frac{1}{\lambda}$$-\lambda$$\lambda$$\frac{1}{\lambda}$ 17. A unit vector perpendicular to the plane containing $\vec{A}=\hat{i}+\hat{j}-2\hat{k}$ and $\vec{B}=2\hat{i}-\hat{j}+\hat{k}$ is$\frac{1}{\sqrt{35}}(-\hat{i}-5\hat{j}-3\hat{k})$$\frac{1}{\sqrt{35}}(-\hat{i}+5\hat{j}-3\hat{k})$$\frac{1}{\sqrt{19}}(-\hat{i}+3\hat{j}-3\hat{k})$$\frac{1}{\sqrt{26}}(-\hat{i}+3\hat{j}-4\hat{k})$ 18. A hemispherical shell is placed on the x-y plane centered at the origin. For a vector field $\vec{E}=\frac{-y\hat{i}+x\hat{j}}{x^2+y^2}$, the value of the integral $\int_S(\vec{\nabla}\times\vec{E})\cdot d\vec{s}$ over the hemispherical surface is$2\pi$$\pi$$4\pi$$0$ 19. Which of the following is not true for Hermite polynomials?$H_3(x)=8x^3-12x+2$$H_2(x)=4x^2-2$$H_1(x)=2x$$H_0(x)=1$ 20. The modulus and phase of the complex number $(1+i)i$ in polar representation are$\sqrt{2}$ and $\frac{3\pi}{4}$$\sqrt{3}$ and $\frac{3\pi}{4}$$\sqrt{2}$ and $\frac{\pi}{4}$$\sqrt{3}$ and $\frac{\pi}{4}$ 21. Consider the differential equation $y^{\prime\prime}+2y^{\prime}+y=0$. If $y(0)=0$ and $y^{\prime}(0)=1$, then the value of $y(2)$ is$\frac{2}{e^2}$$\frac{2}{e}$$\frac{4}{e^2}$$\frac{4}{e}$ 22. Consider a $2\times 2$ matrix M=$\begin{pmatrix}0 & a\\a & b\end{pmatrix}$, where $a,b>0$. ThenA. $M$ is real symmetric matrix.B. One of the eigenvalues of $M$ is greater than $b$.C. One of the eigenvalues of $M$ is negative.D. Product of eigenvalues of $M$ is $b$.Choose the most appropriate answer from the options given below:A, B, CC, DB, DB, C ,D 23. The equation $z^2+\bar{z}^2=4$ in the complex plane (where $\bar{z}$ is the complex conjugate of $z$) representshyperbolaellipsecircle of radius 2circle of radius 4 24. Consider a unit circle $C$ in the xy plane, centered at the origin. The value of the integral $\oint [(\sin x-y) dx - (\sin y- x) dy]$ over the circle $C$, traversed anticlockwise is$0$$2\pi$$3\pi$$4\pi$ 25. Consider a vector field $\vec{F}=y\hat{i}+xz^3\hat{j}-zy\hat{k}$. Let C be the circle $x^2+y^2=4$ on the plane $z=2$, oriented counter-clockwise. The value of the contour integral $\oint \vec{F}\cdot\vec{dr}$ is$28\pi$$4\pi$$-4\pi$$-28\pi$ 26. Let $(x,y)$ denote the coordinates in a rectangular Cartesian coordinate system $C$. Let $(x^{\prime}, y^{\prime})$ denote the coordinates in another coordinate system $C^{\prime}$, defined by$x^{\prime}=2x+3y$$y^{\prime}=-3x+4y$.The area element in $C^{\prime}$ is$\frac{1}{17}dx^{\prime} dy^{\prime}$$12 dx^{\prime} dy^{\prime}$$dx^{\prime} dy^{\prime}$$9 dx^{\prime} dy^{\prime}$ 27. The unit vector perpendicular to the surface $ x^2 + y^2 +z^2=3$ at the point $(1,1,1)$ is$\frac{\hat{i}-\hat{j}+\hat{k}}{\sqrt{3}}$$\frac{\hat{i}+\hat{j}+\hat{k}}{\sqrt{3}}$$\frac{\hat{i}-\hat{j}-\hat{k}}{\sqrt{3}}$$\frac{\hat{i}+\hat{j}-\hat{k}}{\sqrt{3}}$ 28. What is the equation of the plane which is tangent to the surface $xyz=4$ at the point (1,2,2)?$x+2y+4z=12$$4x+2y+z=12$$x+4y+z=0$$2x+y+z=6$ 29. If $\vec{r}$ is a position vector, $r^n\vec{r}$ is solenoidal for$n=-3$$n=3$$n=-2$$n=-1$ 30. Three vectors $\vec{A}$, $\vec{B}$ and $\vec{C}$ are given by $\vec{A}=\alpha\hat{i}-2\hat{j}+2\hat{k}$, $\vec{B}=6\hat{i}+4\hat{j}-2\hat{k}$ and $\vec{C}=-3\hat{i}-2\hat{j}-4\hat{k}$. The value of $\alpha$ for which the vectors will be coplanar is-112-3 31. If $\vec{F}$ is a constant vector and $\vec{r}$ is the position vector then $\vec{\nabla}(\vec{F}\cdot\vec{r})$ would be$(\vec{\nabla}\cdot \vec{r})\vec{F}$$\vec{F}$$(\vec{\nabla}\cdot \vec{F})\vec{r}$$|\vec{r}|\vec{F}$ 32. Let $\vec{r}$ be the position vector of a point on a closed contour C. What is the value of the line integral $\oint\vec{r} \cdot d\vec{r}$ ?10-13 33. The value of the integral $\int_{-\infty}^{\infty} x^2 e^{-ax^2} dx$, where $a>0$ is$\frac{1}{2}\sqrt{\frac{\pi}{a^3}}$$\frac{1}{2} \sqrt{\frac{\pi}{a}}$$\sqrt{\frac{\pi}{2a^3}}$$\sqrt{\frac{\pi}{2a}}$ 34. One of the solutions of the equation $(1-x^2)\frac{d^2y}{dx^2}-2x\frac{dy}{dx}+12y=0$ is$H_4(x)$$P_3(x)$$P_4(x)$$H_3(x)$ 35. The directional derivative of $\phi=x^2y+xz$ at (1,2,-1) in the direction $\vec{A}=2\hat{i}-2\hat{j}+\hat{k}$ is$\frac{5}{3}$$\frac{2}{3}$$\frac{1}{3}$$\frac{5}{2}$ 36. If $\delta(x)$ is Delta function then$x\delta(x)=0$$x\delta(x)=1$$x\delta(x)=\infty$$x\delta(x)=x$ 37. The Fourier transform of $e^{-|x|}$ is$\frac{1}{1+k^2}$$\frac{2}{1+k^2}$$\frac{2}{1+k}$$\frac{1}{1+k}$ 38. The residue of the complex function $f(z)=e^{1/z}$ at $z=0$ is10-12 39. If $J_{1/2}(x)$ are $J_{-1/2}(x)$ are Bessel's functions, the value of $[J_{1/2}(x)]^2+[J_{-1/2}(x)]^2$ is$\frac{1}{\pi x}$$\frac{2}{\pi x}$$\frac{1}{2\pi x}$$\frac{2x}{\pi}$ 40. For the function $f(z)=\frac{z \sin z}{(z-\pi)^3}$, the residue at the pole $z=\pi$ is12-1-2 41. The value of $\Gamma(-3/2)$ is$\infty$$\frac{3}{4}\sqrt{\pi}$$\frac{4}{3}\sqrt{\pi}$Zero 42. If $\vec{r}=x\hat{i}+y\hat{j}+z\hat{k}$ is the position vector, then the value of $\vec{\nabla}(\log r)$ is$\frac{\vec{r}}{r}$$\frac{\vec{r}}{r^2}$$-\frac{\vec{r}}{r^3}$$-\frac{\vec{r}}{r}$ 43. The value of $\alpha$ so that $e^{\alpha y^2}$ is an integrating factor of the differential equation $(e^{-{y^2}/2}-xy)dy-dx=0$ is$-1$$1$$\frac{1}{2}$$-\frac{1}{2}$ 44. The value of $\sqrt{i}+\sqrt{-i}$, where $i=\sqrt{-1}$ is$\sqrt{2}$$\frac{1}{\sqrt{2}}$$0$$-\sqrt{2}$ 45. The value of the integral $\int_C \frac{z^2+1}{(z+1)(z+2)}dz$, where $C$ is $|z|=\frac{3}{2}$ is$\pi i$$0$$2 \pi i$$4\pi i$ 46. Let $P_n(x)$ be the Legendre polynomial of degree $n>1$, then the value of the integral $\int_{-1}^{1}(1+x)P_n(x)dx$ is equal to$0$$1/(2n+1)$$2/(2n+1)$$n/(2n+1)$ 47. Laplace transform of $e^{-2t}\sin 4t$ is$\frac{4}{s^2+4s+20}$$\frac{s-4}{s^2+4s+20}$$\frac{s-2}{s^2+4s+20}$$\frac{2}{s^2+4s+20}$ 48. The value of the integral $\int_{-\pi/2}^{\pi/2} \sin^2\theta\, \delta(3\theta+\pi)\,d\theta$ is$\pi/2$$\pi/4$$1/4$$1/2$ 49. Out of the given equations, the only equation which is an exact differential is$(4x^3 y^3-2xy)dx+(3x^4 y^2-x^2)dy=0$$(x^2+y^2+x)dx+ xy dy=0$$(3e^{3x}-4x)dx +6e^{3x}dy=0$$\cos y dx+ (\sin x-\sin y)dy=0$ 50. The Laplace transform of $t^3 \delta(t-4)$ is$\frac{e^{-4s}}{64}$$\frac{e^{-4s}}{4}$$\frac{e^{-3s}}{4}$$\frac{e^{3s}}{3}$ Loading...