Answer:
The time constant τ = L/R represent the time requiered for the curent to get value of 63 % of its maximun value
Explanation:
In a circuit RL ( serie circuit with a resistor R and the inductor L ) when a voltage is applied the inductor will have a reaction, such reaction consist in the creation of an electromotive force which will prevent the current to get its maximun value. The time constant which in the case of an inductor is
τ = L/R , represent the time requiered for the crrent to be 63 % of its final value
Answer:
let M be the mass of brick
let m be the mass of the pebble
.5M(3)^2 =KE
.5m(5)^2= KE
.5M9 = .5m25
9M = 25m
(9/25)M = m
Answer:
1404 N .
Explanation:
Force = rate of change of momentum
d/dt ( mv₁ - mv₂ )
If v₂ = - v₁
rate of change of momentum
= d/dt ( mv₁+mv₁ )
=2x v₁ dm / dt ( Here velocity of water v₁ throughout is constant )
Force = 2 xv₁ dm / dt
Given ,
v₁ = 18 m/s
dm / dt = rate of flow of mass of water
= 39 kg / s
Putting the values in the equation above
Force = 2xv₁ dm / dt
= 2x18 x 39
= 1404 N .
Correct answer is A.
In a parallel circuit, the voltage is same across all the branches however the current in each branch is different and depends on the resistance of that branch. The higher the resistance, the lower the current.
In a series circuit, the voltage across each resistive element is different and depends on the resistance of that element. Higher the resistance, larger will be the voltage drop. However, the current throughout the series circuit is the same as there is only path in a series circuit.
Points to Remember:
1) In series circuit current remains the same and voltage varies
2) In parallel circuit voltage remains the same and current varies
