Question

One poise is equal to:
A. 100 centipoise
B. 0.1 kg $m^{ -1 }s^{ -1 }$
C. Both A and B
D. 1 kg $m^{ -1 }s^{ -1 }$

Answer 1

Hint: To answer this question you should know that poise is a unit of dynamic viscosity. Now you can write the formula of viscosity and from there you can write the units.

Complete step by step answer:
Now, we will discuss the stepwise answer.

Poise - The poise (P) is the unit of dynamic viscosity (absolute viscosity) in the CGS system of units. This unit is named after Jean Léonard Marie Poiseuille.

Dynamic viscosity - Dynamic viscosity is the measurement of the fluid’s internal resistance to flow.
The formula for dynamic viscosity can be written as,
$\eta \quad =\quad \dfrac { F/A }{ dv/dx }$
Where,
$\eta$ = viscosity
F/A = pressure = unit - N/$m^{ 2 }$
dv/dx = change in velocity of liquid with respect to change in distance travelled by the liquid = unit - $s^{ -1 }$

So, the unit of viscosity ($\eta$) can be written as - N $m^{ -2 }$s or Pa.s or kg $m^{ -1 }s^{ -1 }$

We can convert this SI unit (N $m^{ -2 }$.s) to CGS unit (Poise) as,
1 kg $m^{ -1 }s^{ -1 }$ = 10 P
So, 1 P = 0.1 kg $m^{ -1 }s^{ -1 }$
Also,
1 cP (centipoise) = $10^{ -2 }$ P
1 P = 100 cP

Hence, we can conclude that,
One poise = 100 centipoise = 0.1 kg $m^{ -1 }s^{ -1 }$

Therefore, we can conclude that the correct answer to this question is option C.

Note: We should be aware of the fact that the poise is often used with the metric prefix centi- because the viscosity of water at 20 $^{ 0 }$C (NTP) is almost exactly 1 centipoise.
We already know a centipoise is one-hundredth of poise.