8. In soft magnetic materials such as iron, what happens when an external magnetic field is removed?
a. The domain alignment persists.
b. The orientation of domains fluctuates.
c. The material becomes a hard magnetic material.
d. The orientation of domains changes, and the material returns to an unmagnetized state.
9. According to Lenz’s law, if the applied magnetic field changes,
a. the induced field attempts to keep the total field strength constant.
b. the induced field attempts to increase the total field strength.
c. the induced field attempts to decrease the total field strength.
d. the induced field attempts to oscillate about an equilibrium value.
10. The direction of the force on a current-carrying wire in an external magnetic field is
a. perpendicular to the current only.
b. perpendicular to the magnetic field only.
c. perpendicular to the current and to the magnetic field.
d. parallel to the current and to the magnetic field
Answer:
(a) Current is 2831.93 A
(b) 
(c) 
Explanation:
Length of wire l = 3.22 m
Diameter of wire d = 7.32 mm = 0.00732 m
Cross sectional area of wire
Resistance 
Potential difference V = 33.7 volt
(A) current is equal to
(B) Current density is equal to
(c) Resistance is equal to
, to hit nails into a piece of wood or a wall, or to break things into pieces.
Answer:
29.4855 grams of chlorophyll
Explanation:
From Raoult's law
Mole fraction of solvent = vapor pressure of solution ÷ vapor pressure of solvent = 457.45 mmHg ÷ 463.57 mmHg = 0.987
Mass of solvent (diethyl ether) = 187.4 g
MW of diethyl ether (C2H5OC2H5) = 74 g/mol
Number of moles of solvent = mass/MW = 187.4/74 = 2.532 mol
Let the moles of solute (chlorophyll) be y
Total moles of solution = moles of solute + moles of solvent = (y + 2.532) mol
Mole fraction of solvent = moles of solvent/total moles of solution
0.987 = 2.532/(y + 2.532)
y + 2.532 = 2.532/0.987
y + 2.532 = 2.565
y = 2.565 - 2.532 = 0.033
Moles of solute (chlorophyll) = 0.033 mol
Mass of chlorophyll = moles of chlorophyll × MW = 0.033 × 893.5 = 29.4855 grams
Answer:
960 m
Explanation:
Given that,
- Speed = 120 m/s
- Time taken = 4 minutes
We have to find the distance covered.
Firstly, let's convert time in seconds.
→ 1 minute = 60 seconds
→ 4 minutes = (4 × 60) seconds
→ 4 minutes = 240 seconds
Now, we know that,
→ Distance = Speed × Time
→ Distance = (4 × 240) m
→ Distance = 960 m
Therefore, distance covered is 960 m.
