**MCQs Questions for Class 12 Maths Chapter 9 Differential Equations**

In this 21^{st} century, Multiple Choice Questions (MCQs) play a vital role to prepare for a competitive examination. CBSE board has also brought a major change in its board exam patterns.

In most of the competitive examinations, only MCQ questions are asked. So, for getting ready for the competitive examinations, we have to practice for MCQ questions to solve. It strengthens the critical thinking and problem solving skills.

In future, if you want to prepare for competitive examination and to crack it, then you should more focus on the MCQ questions. Thus, from the board examinations point of view and competitive examinations point of view, you should practice more on multiple choice questions.

Thus, let’s solve these MCQs Questions to make our foundation very strong.

**MCQs Questions for Class 12 Maths Chapter 9 Differential
Equations**

**1.** The radius of
a circle is increasing at the rate of 0.4 cm/s. The rate of increasing of its
circumference is

(a) 0.8 cm/s

(b) 0.4 Ï€ cm/s

(c) 0.8 Ï€ cm/s

(d) None of these

**Answer:**** c**

**2.** The solution
of the differential equation: (e^{y} + 1) cos x
dx + e^{y} sin x dy = 0 is

(a) (e^{y} + 1) sin x
= c

(b) e^{x} sin x = c

(c) (e^{x} + 1) cos x
= c

(d) none of these

**Answer:
a**

**3. **The order of
the differential equation: y’ – 20 y + 2 = 0 is

(a) 2

(b) 1

(c) 3

(d) 4

**Answer:**** b**

4. Find the order and degree of the
differential equation: y”’ – (4y’)^{3 }= 0.

(a) Order -3, Degree-1

(b) Order -1, Degree-3

(c) Order -2, Degree-1

(d) Order -3, Degree-2

**Answer:**** a**

**5.** The
solution of the differential equation: x dy – y dx = Q represents

(a) a rectangular hyperbola

(b) parabola whose vertex is at origin

(c) straight line passing through origin

(d) a circle whose centre is at origin

**Answer:**** c**

**6.** If
sin x dy/dx + y cos x = x sin x,
then (y – 1) sin x equals

(a) c – x sin x

(b) c + x cos x

(c) c – x cos x

(d) c + x sin x

**Answer:
c**

**7. **The order of
the differential equation: dy/dx + 15 sin x
= 0 is

(a) 1

(b) 2

(c) 3

(d) 4

**Answer:**** a**

**8. **The solution of the differential equation: tan y sec² x dx + tan x sec² y dy
+ 0 is

(a) tan x + tan y = k

(b) tan x – tan y = k

(c) tanx/tany =
k

(d) tan x.tan y = k

**Answer:**** d**

**9. **The integrating
factor of the differential equation: dy/dx + y tan x – sec x = 0 is

(a) cos x

(b) sec x

(c) e^{cos x}

(d) e^{sec x}

**Answer:
b **

**10. **Which of the
following is a second order differential equation?

(a) (y’)² + x = y²

(b) y’y” + y = sin x

(c) y” + (y”)² + y = 0

(d) y’ = y²

**Answer:**** b **

**11. **

**Answer:**** c**

**12. **

**Answer:**** d**

**13. **The solution of
the differential equation: dy/dx = (6x + 9y – 7)/(2x + 3y – 6) is

(a) -c/3

(b) 3c/2

(c) 2c/3

(d) -2c/3

**Answer:**** a**

**14. **The general
solution of the differential equation: e^{x} cos y dx – e^{x} sin
y dy = 0 is

(a) e^{x} cos y = k

(b) e^{x} sin y = k

(c) e^{x} = k cos y

(d) e^{x} = k sin y

**Answer:**** a**

**15. **Which of the
following is the general solution of

**Answer:**** a**