Content text IIT-JAM Differential Equation DPP Sheet 03.pdf
2 North Delhi : 56-58, First Floor, Mall Road, G.T.B. Nagar (Near Metro Gate No. 3), Delhi-09, Ph: 011-41420035 South Delhi : 28-A/11, Jia Sarai, Near-IIT Metro Station, New Delhi-16, Ph : 011-26851008, 26861009 Q.4. The solution of the differential equation '' y y 4 0 subjected to the condition y 0 1, ' y 0 2 is (a) sin 2 cos 2 x x (b) sin 2 cos 2 x x (c) 1 sin 2 cos 2 2 x x (d) 1 sin 2 cos 2 2 x x Q.5. The solution of the differential equation 2 2 2 0 d x dx x dt dt , which satisfies x 0 3 and does not blow up as t , will be (a) 3 t x e (b) 2 4 t t e e x (c) 2 3 t x e (d) 2 2 t t x e e Q.6. The general solution of the differential equation 5 4 3 2 5 4 3 2 3 3 0 d y d y d y d y dx dx dx dx is (a) 2 1 2 3 4 5 x c c x c c x c x e (b) 2 2 3 1 2 3 4 5 x x x c x c x c e c e c e (c) 1 2 3 4 5 x c c c c c e (d) None of these Q.7. The general solution of the differential equation 3 2 3 2 9 27 27 0 d y d y dy y dx dx dx is (a) 2 3x y x A Bx Cx e (b) 2 3x y x A Bx Cx e (c) 3 3 3 x x x y x Ae Be Ce (d) 3 3 3 x x x y x Ae Be Ce Q.8. The general solution of the differential equation 4 4 4 d y m y dx is (a) 1 2 3 4 y x C mx C mx C mx C mx cos sin cosh sinh (b) 1 2 3 4 cos sin mx y x C mx C mx C C x e (c) 2 3 1 2 3 4 mx y x C C x C x C x e (d) 1 2 3 4 cosh sinh mx y x C C x e C mx C mx Q.9. The solution of the ordinary differential equation 2 2 0 d y dy p qy dx dx is 3 1 2 x x y C e C e . The value of p and q are respectively (a) 3, 3 (b) 3, 4 (c) 4, 3 (d) 4, 4 Q.10. If 6 and -9 are the roots of the auxiliary equation, then the differential equation can be represented as (a) 2 2 4 12 0 d y dy y dx dx (b) 2 2 4 12 0 d y dy y dx dx (c) 2 2 3 54 0 d y dy y dx dx (d) 2 2 3 54 0 d y dy y dx dx
3 North Delhi : 56-58, First Floor, Mall Road, G.T.B. Nagar (Near Metro Gate No. 3), Delhi-09, Ph: 011-41420035 South Delhi : 28-A/11, Jia Sarai, Near-IIT Metro Station, New Delhi-16, Ph : 011-26851008, 26861009 Q.11. A function n(x) satisfies the differential equation 2 2 2 0 d n x n x dx L , where L is a constant and subjected to the conditions n K 0 and n 0 . The solution of the equation will be (a) x L/ n x Ke (b) x L/ n x Ke (c) x L / n x Ke (d) x L / n x Ke Q.12. The solution to the differential equation 2 2 d u du k dx dx , where k is constant, subjected to the boundary conditions 0 u u L u 0 0, , is (a) 0 x u u L (b) 0 1 1 kx kL e u u e (c) 0 1 1 kx kL e u u e (d) 0 1 1 kx kL e u u e Q.13. Consider the differential equation: 2 2 0 d y y dt with initial conditions y 0 1, 0 1 t dy dt for 0 t . The solution attains a maximum for t equal to (a) 4 t (b) 2 t (c) t 0 (d) t Q.14. The differential equation 2 2 0 d y y dx satisfying the conditions y y 0 1, 0 , has (a) a unique solution (b) infinite no.of solutions (c) no solution (d) none of these Q.15. A solution of the ordinary differential equation 2 2 5 6 0 d y dy y dx dx is such that 3 3 1 0 2 and 1 e y y e . The value of 0 dy dx is (a) 1 (b) e (c) e2 (d) -3 Q.16. If the characteristic equation of the differential equation 2 2 2 0 d y dy y dx dx has two equal roots, then the values of are (a) +1, -1 (b) 0, -1 (c) 0, 1 (d) +1/2, -1/2 Q.17. Consider the following differential equation: 2 2 8 6 0 with 0 1and Lim 0 x d y i y y y x dx The value of y 2 is (a) 6 e (b) 6 e (c) 6 e (d) 6 e