Answer:
1) The strength of the electromagnet increases → Place a magnetic core inside the coil of wire
2) The electromagnet turns off → Turn off the battery supply
3) The poles of the electromagnet reverse → Change the direction in which the current flows
Explanation:
when current passes through a coil it behaves a an electromagnet.
Magnetic field strength is given by
B = μ N I
N is no of turns and
I is the current through coil
μ is permeability of the medium or core in the coil.
1). Magnetic core increase permeability μ so it will strengthen magnetic field:
B = <u>μ</u> N I
2). When the battery turns off current becomes zeroi.e I=0
So B = μ N * 0
⇒ B = 0
so electromagnet turns off
3). Direction of magnetic field can be determine by right hand rule, i.e curl the fingers in the direction of current, thumb will point in the direction of north pole.
so changing current direction will change direction of magnetic field.
Answer:
dam/hydro power
Explanation:
estuary is the place where rivers meet the ocean, there are a lot of currents there (waves...) so it likely means thery use a dam or some sort of way of collecting electricity from the motion of the water there. many birds live in estuaries because of being able to find fish to feed from
The correct option is C.
From the information given above, one can easily conclude that electromagnetic Y is the strongest because, it produces the higher amount of current compare to the other electromagnets. Electromagnet W is the weakest because it produces the lowest amount of current.
The velocity of the tip of the second hand is 0.0158 m/s
Explanation:
First of all, we need to calculate the angular velocity of the second hand.
We know that the second hand completes one full circle in
T = 60 seconds
Therefore, its angular velocity is:
![\omega = \frac{2\pi}{T}=\frac{2\pi}{(60)}=0.105 rad/s](https://tex.z-dn.net/?f=%5Comega%20%3D%20%5Cfrac%7B2%5Cpi%7D%7BT%7D%3D%5Cfrac%7B2%5Cpi%7D%7B%2860%29%7D%3D0.105%20rad%2Fs)
Now we can calculate the velocity of a point on the tip of the hand by using the formula
![v=\omega r](https://tex.z-dn.net/?f=v%3D%5Comega%20r)
where
is the angular velocity
r = 15 cm = 0.15 m is the radius of the circle (the distance of the point from the centre of rotation)
Substituting,
![v=(0.105)(0.15)=0.0158 m/s](https://tex.z-dn.net/?f=v%3D%280.105%29%280.15%29%3D0.0158%20m%2Fs)
Learn more about angular motion here:
brainly.com/question/9575487
brainly.com/question/9329700
brainly.com/question/2506028
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