# If the rate of change in the area of a circle is π sq. cm/sec, then the rate of change in the radius of the circle when the radius is 10 cm is

1.  π cm/sec

2.  0.05cm/sec

3.   0.2πcm/sec

4.  3 cm/sec

4

0.05cm/sec

Explanation :
No Explanation available for this question

# When a circular oil drop expands on water, its area increases at the uniform rate of 40sq. cm per minute. The rate of increase in the radius when the radius 5 cm is

1.  4/π cm/m

2.  1/200 cm/m

3.  8cm/m

4.   4 cm/ma

4

4/π cm/m

Explanation :
No Explanation available for this question

# A stone is dropped into a quiet pond and waves move in circles outward from the place where it strikes, at a speed of 30 cm per second. At the instant when the radius of the wave ring is 50mt, the rate of increase in the area of

1.  0.75sq.cm/sec

2.   30sq.cm/sec

3.  30πsq.cm/sec

4.  0.4πsq.cm/sec

4

30πsq.cm/sec

Explanation :
No Explanation available for this question

# A stone is dropped into a quiet pond and waves move in circles outward from the place where it strikes, at a speed of 30 cm per second. At the instant when the radius of the wave ring is 50 mt, the rate increase in the circumfere

1.  0.6πm/sec

2.  6πm /sec

3.  0.65πm/sec

4.  6 π cm /sec

4

0.6πm/sec

Explanation :
No Explanation available for this question

# If the rate of change of area of a circle is equal to the rate of change of its diameter then its radius =

1.  2/π

2.   1/π

3.  π/2

4.  π

4

1/π

Explanation :
No Explanation available for this question

# The side of a square increases at the rate of 1 cm per second. The rate at which perimeter increases is

1.   2 cm/sec

2.  4cm /sec

3.   5 cm/sec

4.  3 cm/sec

4

4cm /sec

Explanation :
No Explanation available for this question

# If the rate of change of the side of a square is 0.05 cm/sec, then the rate of change in the area of the square when the side is 10 cm is

1.  0.5sq.cm/sec

2.  1sq.cm/sec

3.  5sq.cm/sec

4.  10sq.cm/sec

4

1sq.cm/sec

Explanation :
No Explanation available for this question

# The period of cos4 x is

1.  π

2.  2π

3.  π/2

4.  3π

4

π

Explanation :
No Explanation available for this question

# The period of 5 cos 3x+ 3 tan 3x is

1.  π

2.  2π/3

3.  π/2

4.  2π

4

2π/3

Explanation :
No Explanation available for this question

1.  2πc

2.  πc

3.  4πc

4.  none

4