(A)
Explanation:
We can see that the resistors are connected in parallel so all of them have the same voltage of 100 V. We also know that

Since resistor Y dissipates 100 W of power, we can solve for the current as

Answer:
Therefore,
The frequency heard by the engineer on train 1

Explanation:
Given:
Two trains on separate tracks move toward each other
For Train 1 Velocity of the observer,

For Train 2 Velocity of the Source,

Frequency of Source,

To Find:
Frequency of Observer,
(frequency heard by the engineer on train 1)
Solution:
Here we can use the Doppler effect equation to calculate both the velocity of the source
and observer
, the original frequency of the sound waves
and the observed frequency of the sound waves
,
The Equation is

Where,
v = velocity of sound in air = 343 m/s
Substituting the values we get

Therefore,
The frequency heard by the engineer on train 1

Answer:
Explanation:
N = 65
Area, A = 0.1 x 0.2 = 0.02 m^2
R = 10 ohm
ω = 29.5 rad/s
B = 1 T
(a) at t = 0
e = N x B x A x ω
e = 65 x 1 x 0.02 x 29.5
e = 38.35 V
(b) The maximum rate of change of magnetic flux is equal to the maximum value of induced emf.
Ф = 38.35 Wb/s
(c) e = NBAω Sinωt
e = 65 x 1 x 0.02 x 29.5 x Sin (29.5 x 0.05)
e = 38.174 V
(d) Maximum torque
τ = M B Sin 90
τ = N i A B
τ = N e A B / R
τ = 65 x 38.35 x 0.02 x 1 / 10
τ = 5 Nm