The answer is the option c. generator. Generator is a machine that
converts mechanical energy into electricity. The way it is made is
because the mechanical movement may be transformed in rotation of
magnets placed inside a coiled wire, and this induces the movement of
electrons through the coiled wire. As you know electricity is the flow
of electrons.
Answer:
The magnetic field through the wire must be changing
Explanation:
According to Faraday's law, the induced emf, ε in a metallic conductor is directly proportional to the rate of change of magnetic flux,Φ through it. This is stated mathematically as ε = dΦ/dt.
Now for the wire, the magnetic flux through it is given by Φ = ABcosθ where A = cross-sectional area of wire, B = magnetic field and θ = angle between A and B.
So, dΦ/dt = dABcosθ/dt
Since A and B are constant,
dΦ/dt = ABdcosθ/dt = -(dθ/dt)ABsinθ
Since dθ/dt implies a change in the angle between A and B, since A is constant, it implies that B must be rotating.
So, <u>for an electric current (or voltage) to be produced in the wire, the magnetic field must be rotating or changing</u>.
Answer: (d)
Explanation:
Given
Mass of object 
Speed of object 
Mass of object at rest 
Suppose after collision, speed is v
conserving momentum
Initial kinetic energy
Final kinetic energy
So, it is clear there is decrease in kinetic energy . Thus, energy decreases and velocity becomes 2 m/s.
Answer:
-4.71 m/s
Explanation:
Given:
y₀ = 1.13 m
y = 0 m
v₀ = 0 m/s
a = -9.8 m/s²
Find: v
v² = v₀² + 2a (y − y₀)
v² = (0 m/s)² + 2(-9.8 m/s²) (0 m − 1.13 m)
v = -4.71 m/s
