Answer:
<h3>The 28 loops wound on the square armature</h3>
Explanation:
Peak output voltage
V
Area of square armature 
Magnetic field
T
Angular frequency 
According to the law of electromagnetic induction,

Where
number of loops of wire.

≅ 28
Thus, 28 loops of wire should be wound on the square armature.
We have to covert 512 cal of heat in kilo joules.
As, 1 cal = 0.004184 kJ = 4.184 joules.
Therefore,

Thus, combustion of a small wooden match produces approximately ( in kilo joules ) is 2.142 kJ .
Answer:
0.6 Ω
Explanation:
As shown in the diagram below,
Since the resistance and the ammeter are connected in series,
(i) The same amount of current flows through them.
(ii) The sum of their individual individual voltage is equal to the total voltage of the circuit.
Applying ohm's law,
V = IR................ Equation 1
Where V = Voltage across the ammeter, I = current flowing through the ammeter, R = resistance of the ammeter.
make R the subject of the equation
R = V/I............... Equation 2
Given: V = 1.2-0.9 = 0.3 V, I = 0.5 A.
Substitute into equation 2
R = 0.3/0.5
R = 0.6 Ω
Answer:
The nail will stick to the bar magnet because it will become magnetized, and it's metal. The presence of the nearby north pole rearranges the magnetic domains inside the steel so that their south poles all point toward the north pole of the permanent magnet. As a result, the other end of the nail becomes a north pole.Magnets attract iron due to the influence of their magnetic field upon the iron. ... When exposed to the magnetic field, the atoms begin to align their electrons with the flow of the magnetic field, which makes the iron magnetized as well. This, in turn, creates an attraction between the two magnetized objects.