1
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

A spherical iron ball 10 cm in radius is coated with a layer of ice of uniform thickness, which melts at a rate of 50 cm$$^3$$ /min. When the thickness of the ice is 15 cm, the rate at which the thickness of ice decreases is ........ cm/min.

A
5/6$$\pi$$
B
1/54$$\pi$$
C
1/18$$\pi$$
D
1/36$$\pi$$
2
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

Find the minimum value of $$2x+3y$$, when $$xy=6$$.

A
9
B
12
C
8
D
6
3
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

The volume of a spherical balloon is increasing at the rate of $$30 \mathrm{~cm}^3$$ per minute. Find the rate of change of surface area of the balloon, when its radius is $$6 \mathrm{~cm}$$.

A
$$5 \mathrm{~cm}^2 / \mathrm{min}^{-1}$$
B
$$30 \mathrm{~cm}^2 / \mathrm{min}^{-1}$$
C
$$10 \mathrm{~cm}^2 / \mathrm{min}^{-1}$$
D
$$20 \mathrm{~cm}^2 / \mathrm{min}^{-1}$$
4
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

If $$g(x)=\frac{1}{6} f\left(3 x^2-1\right)+\frac{1}{2} f\left(1-x^2\right), \forall x \in R$$, where $$f^{\prime \prime}(x) > 0, \forall x \in R$$. Then, $$g(x)$$ is increasing in the interval

A
$$\left(\frac{-1}{\sqrt{2}}, 0\right) \cup\left(\frac{1}{\sqrt{2}}, \infty\right)$$
B
$$\left(\frac{-1}{\sqrt{2}}, \frac{1}{\sqrt{2}}\right)$$
C
$$(-1,0) \cup(1,2)$$
D
$$\left(-\infty, \frac{-1}{\sqrt{2}}\right) \cup\left(\frac{1}{\sqrt{2}}, \infty\right)$$