Answer:
The minimum frequency of the coil is 7.1 Hz
Explanation:
Given;
number of turns, N = 200 turns
cross sectional area, A = 300 cm² = 300 x 10⁻⁴ m²
magnitude of magnetic field strength, B = 30 x 10⁻³ T
maximum value of the induced emf, E = 8 V
Maximum induced emf is given as;
E = NBAω
where
ω is angular velocity (ω = 2πf)
E = NBA2πf
where;
f is the minimum frequency, measured in hertz (Hz)
f = E / (NBA2π)
f = 8 / (200 x 30 x 10⁻³ x 300 x 10⁻⁴ x 2 x 3.142)
f = 7.073 Hz
f = 7.1 Hz
Therefore, the minimum frequency of the coil is 7.1 Hz
Answer:
0.000225 m
Explanation:
Coefficient of linear expansion = 
Length = 0.3 meters
ΔT = Change in temperature = 250 °C
Linear expansion

Change in length of the Pyrex glass dish is 0.000225 m.
Answer:
Atoms with the same number of protons but with different electrical charges are different ions
Explanation:
Ions are defined as those atoms or molecules which carry charge
Answer:
Repel one another
Explanation
I am assuming you meant "two north poles will do this" Or something similar.
because you can't isolate poles, so a magnet wouldn't be just north
ANYWAYS i say repel because like terms repel, opposites attract.
I am quite sure the first one is Friction, but I am not sure about the second one. Is it wind?