Answer:
<em>Positives (advantages) of Friction:</em>
Friction is responsible for many types of motion -
- It helps us walk on the ground
- Brakes in a car make use of friction to stop the car
- Asteroids are burnt in the atmosphere before reaching Earth due to friction.
- It helps in the generation of heat when we rub our hands.
<em>Negatives (disadvantages) of Friction:</em>
- Friction produces unnecessary heat leading to the wastage of energy.
- The force of friction acts in the opposite direction of motion, so friction slows down the motion of moving objects.
- Forest fires are caused due to the friction between tree branches.
- A lot of money goes into preventing friction and the usual wear and tear caused by it by using techniques like greasing and oiling.
Answer:
false
explanation:
Answer:
Due to polarization of charges on either side the dielectric, it produces an electric field of its own which acts in a firection opposite to that of the field due to the source.
<h2>Answer: True </h2><h2 />
Faraday's Law (also known as Faraday's Law of Electromagnetic Induction) was formulated from the experiments made by him and states that:
<em>The voltage induced in a closed circuit is directly proportional to the speed with which the magnetic flux that crosses any surface with the circuit as edge changes in time
</em>
<em></em>
where:
is the Electric Field
is the infinitesimal element of the C contour
is the magnetic field density
is an arbitrary surface, whose edge is C
The negative sign indicates the direction of the induced current and refers to the opposition between the fields induced by the magnetic flux and the electromotive force. In addition, its consequences are also expressed in the Lenz law, which states that the induced electricity will be in a direction such that it opposes the variation of the magnetic flux that produced it as a consequence of the principle of conservation of energy.
Therefore:
<h2>If he minus sign were not in Faraday's law it would lead to a violation of the law of conservation of energy
</h2>
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