The correct answer is D. I alread took this test.
Answer: 0.01 m
Explanation: The formulae for capillarity rise or fall is given below as
h = (2T×cosθ)/rpg
Where θ = angle mercury made with glass = 50°
T = surface tension = 0.51 N/m
g = acceleration due gravity = 9.8 m/s²
r = radius of tube = 0.5mm = 0.0005m
p = density of mercury.
h = height of rise or fall
From the question, specific gravity of density = 13.3
Where specific gravity = density of mercury/ density of water, where density of water = 1000 kg/m³
Hence density of mercury = 13.3×1000 = 13,300 kg/m³.
By substituting parameters, we have that
h = 2×0.51×cos 50/0.0005×9.8×13,300
h = 0.6556/65.17
h = 0.01 m
Answer:
Torque,
Explanation:
Given that,
The loop is positioned at an angle of 30 degrees.
Current in the loop, I = 0.5 A
The magnitude of the magnetic field is 0.300 T, B = 0.3 T
We need to find the net torque about the vertical axis of the current loop due to the interaction of the current with the magnetic field. We know that the torque is given by :
Let us assume that, 
is the angle between normal and the magnetic field, 
Torque is given by :
So, the net torque about the vertical axis is 
. Hence, this is the required solution.
