Question

Given figure shows $U$-shaped tube with two hands $A$ and $B$ separated by a semi-permeable membrane.

(i) Adding solute to the right side lowers the value of ${\Psi }_s$ causing water to move to the right side of the tube.
(ii) Applying positive pressure to the left side decreases the value of ${\Psi }_p$ causing water to move to the right side of the tube.
(iii) Applying negative pressure to the left side decreases the value of ${\Psi }_p$ causing water to move to the right side of the tube.
Which of the above statements is/are true ?

• A. (i) and (ii)
• B. (i) only
• C. (iii) only
• D. (i), (ii) and (iii)

Answer 1

Answer: (B)

According to the given figure, if solute is added to the right side, ${\Psi }_s$ lowers. This causes water to move to the right side of the tube. When positive pressure is applied to the left side, ${\Psi }_p$ increases causing water to move to the right side of the tube. Similarly, when negative pressure is applied to the left side, ${\Psi }_p$ lowers, which causes water to move to the left side of the tube.