Q.

A spherical body of radius r and density σ falls freely through a viscous liquid having density ρ and viscosity η and attains a terminal velocity v0. Estimated maximum error in the quantity η is: (Ignore errors associated with σ, ρ and g,gravitational acceleration)   [2026]

1 2[Δrr-Δv0v0]  
2 2[Δrr+Δv0v0]  
3 2Δrr-Δv0v0  
4 2Δrr+Δv0v0  

Ans.

(4)

V0=2r2g9n(ρB-ρL)

n=2r2g9V0(ρB-ρL)

Δnn=2Δrr+ΔV0V0