Water poured into an inverted conical vessel of which the radius of the base is 2 m and height 4 m, and the rate of 77 litres/minute. The rate at which the water level is rising at the instant when the depth is 70 cm is: (use π=22/7)
A
10cm/min
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
20cm/min
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
40cm/min
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
None
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is B20cm/min Given,
R=2m=200cm
H=4m=400cm
1Litre=1000cm3
V=volume of Cone
dVdt=77litreminute
dVdt=77×1000cm3minute
VolumeofCone=13×227×r2h
Differentiating V with respect to t keeping r as constant and h as variable,