Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
COMEDK2023Evening ShiftMathematicsApplication of DerivativesActual

If the volume of a sphere is increasing at a constant rate, then the rate at which its radius is increasing is

Options

  1. Aproportional to the radius
  2. Binversely proportional to its surface area
  3. Cinversely proportional to the radius
  4. Da constant

Correct answer

B. inversely proportional to its surface area

Step-by-step solution

The volume V of a sphere of radius r is given by V = 4 3 r³ . Differentiating both sides with respect to time t , we get dV dt = 4 r² dr dt . It is given that the volume is increasing at a constant rate, so dV dt = k , where k is a positive constant. Substituting this into the derivative equation, k = 4 r² dr dt . Solving for the rate of change of the radius, dr dt = k 4 r² . Since 4 r² is the surface area S of the sphere, we have dr dt = k S . This implies that the rate at which the radius is increasing is inverse

Practice Application of Derivatives on Quantrex Academy →

More from Application of Derivatives

Consider the quadratic equation a x^2+b x+c=0 , where 2 a+3 b+6 c=0 and let g(x)= a x^3 3 + b x^2 2 +c x . Statement-I : The given quadratic equation ax ^2+ bx + c =0 has at least 2025The difference between the absolute maximum and absolute minimum values of the function f(x)=2 x^3-15 x^2+36 x-30 on [-1,4] is 2025If f(x)=x e^ x(1-x) , x R , then f(x) is 2025The angle between the curves y ^2= x and x ^2= y at the point (1,1) is 2025If the tangent of the curve 4 y^3=3 a x^2+x^3 drawn at the point (a, a) forms a triangle of area 25 24 sq.units with the coordinate axes then a = 2025If the function f(x)= x- ^2 x is defined on the interval [- , ] , then f is strictly increasing in the interval 2025If the Lagrange's mean value theorem is applied to the function f(x)=e^x defined on the interval [1,2] and the value of c (1,2) is k , then e^ k-1 = 2025If the tangent to the curve x y+a x+b y=0 at (1,1) makes an angle Tan ⁻¹ 2 with X -axis, then ab a + b = 2025 Full Application of Derivatives list All COMEDK PYQs