Answer:
The behavior of droplets trapped in geometric structures is essential to droplet manipulation applications such as for droplet transport. Here we show that directional droplet movement can be realized by a V-shaped groove with the movement direction controlled by adjusting the surface wettability of the groove inner wall and the cross sectional angle of the groove. Experiments and analyses show that a droplet in a superhydrophobic groove translates from the immersed state to the suspended state as the cross sectional angle of the groove decreases and the suspended droplet departs from the groove bottom as the droplet volume increases. We also demonstrate that this simple grooved structure can be used to separate a water-oil mixture and generate droplets with the desired sizes. The structural effect actuated droplet movements provide a controllable droplet transport method which can be used in a wide range of droplet manipulation applications.
Explanation:
BOOM NOW I WINNNNNNNNNNNn
Answer:
The net magnetic field ta the center of square is
.
Explanation:
Current, I = 12 A , side ,a = 10 cm = 0.1 m
Let the magnetic field due to the one side is B.
The magnetic field is given by
Net magnetic field at the center of the square is
B' = 4 B
Answer:
The torque on the loop is 
Nm
Explanation:
Given:
Current 
A
Magnetic field 
T
Area of loop 
Angle between magnetic field and area vector 
21°
Form the formula of torque in case of magnetic field,
г 
Where 
magnetic moment
г 
г 
г 
Nm
Therefore, the torque on the loop is Nm
How many mL is an espresso?
One shot of espresso is generally about 30–50 ml (1–1.75 oz), and contains about 63 mg of caffeine (3). Important point: The “golden ratio” for espresso is this: a single shot is 30 to 44 mL (1 to 1.5 ounces) of water and 7 grams of coffee
