Explanation:

From the above question, it is clear that the given circuit is capacitive in nature, therefore, the current is leading the voltage by 10°. Hence,

I = Im sin⁡(ωt − 15° + 10°)

=  I = Im sin⁡(ωt – 5°) amps

Explanation:

Average Value Of Alternating Current

The average value is the DC value that produces the same charge as it is produced by an AC source in the given circuit for the given time.

Thus the average value of an alternating quantity = 0.637 x the maximum value of that alternating quantity.

NOTE: Average value for a sinusoidal wave cannot be calculated over a complete cycle as it is zero so it is calculated over half cycle from 0 to 180 degrees. 

Explanation:

• According to Lenz’s law, the induced EMF sets up a current in such a direction so as to oppose the very cause of producing it. Mathematically this expression is expressed in the negative sign
• So, In Faraday’s law, the negative sign shows that the polarity of induced emf is such that it opposes any change in the magnetic flux of the coil.

Explanation:

Coefficient of coupling or magnetic coupling coefficient is (K) is given as

Where L1 and L2 are self-inductance of coil 1 and 2 respectively

Explanation:

Temperature Coefficient of Copper

The  formula for temperature effects on resistance is

R = R_ref [1 + α(T – T_ref)]

Where

R = Conductor resistance at temperature T

R_ref = Conductor resistance at reference temperature “Tref” usually 20°C

α = Temperature coefficient of the resistance of the conducting material

T = Conductor temperature in degree

T_ref = Reference temperature for α is specified

The temperature coefficient for some common materials are listed below (@ 20ºC):

Explanation:

The above figure shows the circuit diagram of DC shunt generator where

I_A = Armature current

I_L = Load current

I_F = Field current

R_A = Armature Resistance

In the shunt generator, the field winding is connected parallel to the armature winding. When the load is connected across the armature, then there exists a voltage drop in field as well as armature winding. The voltage drop appears to IaRa armature reaction and weakened flux.

• The load characteristics of DC shunt generator is also called as the external characteristics and It will only be slightly shifted from the internal characteristic as I_L = I_a — I_f where I_f (field current) is usually very small.

Explanation:

1 HP=745.7 Watt of Power

2 HP = 1491.4 Watt of Power

So, 2 HP  motor working for 5 hours = 1491.4 x 5= 7457 Watt-hour

To convert Watt-Hour into Watt-sec multiply it by 3600

7457 x 3600 = 26845200

= 2.68452×10 ⁷ watt-seconds

Explanation:

f = 1/ t

t = 1 /40

= 0.025 sec

Explanation:

Permanent capacitor run single phase IM

• In a permanent capacitor run, single phase Induction motor a single capacitor is connected in series with the auxiliary winding permanently thus the winding and the capacitor remains energized for both starting and running purpose.
• Therefore permanent capacitor motor behaves virtually like the two-phase motor which is running on a single-phase supply.
• The starting torque of this motor is very low as compared to the capacitor start motor and capacitor start run motor.
• Since the same capacitor is used for the starting and running purpose, therefore, it is called a Permanent capacitor run single phase IM

Explanation:

Electromagnetic Damping :

• The movement of the coil in a magnetic field produces the eddy current in the metal former which further generates another magnetic field and interacts with the original magnetic field. Hence it produces a torque that opposes the motion of conducting coil and plate. Thus the magnitude of the current and the damping torque is dependent on the resistance of the circuit.

Voltage Multiplier

• Multipliers are non-inductive high resistances connected in series with the voltmeter for the purpose of increasing the range of the voltmeter.

The resistance of the Multiplier greatly exceeds the meter’s internal resistance hence it reduces the electromagnetic damping action on the meter movement. The electromagnetic damping can be improved by shunting the meter with a capacitor, but this method increases the meter’s settling time.