This is because of of the heating effect of a current. The glow is a result of current passing through the filament. The current experiences resistance as a result heat is generated. When resistance is at zero, there potential differences is not needed hence temperature generated will be at a constant.
Answer:
E_total = 1.30 10¹⁰ C / m²
Explanation:
The intensity of the electric field is
E = k q / r²
on a positive charge proof
The total electric field at the midpoint is
as q₁= 6 10⁻⁶ C the field is outgoing to the right
for charge q₂ = -3 10⁻⁶ C, the field is directed to the right, therefore
E_total = E₁ + E₂
E_total = k q₁ / r₁² + k q₂ / r₂²
r₁ = r₂ = r = 4 10⁻² m
E_total = k/r² (q₁ + q₂)
we calculate
E_total = 9 10⁹ / (4 10⁻²)² (6.0 10⁻⁶ +3.0 10⁻⁶)
E_total = 1.30 10¹⁰ C / m²
Answer:
v = 0.41 m/s
Explanation:
- In this case, the change in the mechanical energy, is equal to the work done by the fricition force on the block.
- At any point, the total mechanical energy is the sum of the kinetic energy plus the elastic potential energy.
- So, we can write the following general equation, taking the initial and final values of the energies:

- Since the block and spring start at rest, the change in the kinetic energy is just the final kinetic energy value, Kf.
- ⇒ Kf = 1/2*m*vf² (2)
- The change in the potential energy, can be written as follows:

where k = force constant = 815 N/m
xf = final displacement of the block = 0.01 m (taking as x=0 the position
for the spring at equilibrium)
x₀ = initial displacement of the block = 0.03 m
- Regarding the work done by the force of friction, it can be written as follows:

where μk = coefficient of kinettic friction, Fn = normal force, and Δx =
horizontal displacement.
- Since the surface is horizontal, and no acceleration is present in the vertical direction, the normal force must be equal and opposite to the force due to gravity, Fg:
- Fn = Fg= m*g (5)
- Replacing (5) in (4), and (3) and (4) in (1), and rearranging, we get:


- Replacing by the values of m, k, g, xf and x₀, in (7) and solving for v, we finally get:

Answer:
2.7s
Explanation:
The solution of time required is shown below:-
In the RC circuit condenser charge 63 percent of the full charge from initial time to constant time
Now, the
63% that is equal to 0.63 which is full equilibrium charge
Therefore, the time required to maintain will be Equal to time (t) constant that is 2.7s
So, the correct answer is 2.7s