### AC Fundamentals Objectives Part 07

**120 ** The frequency of the current will be **60 Hz**.

**121 ** The phase angle between the current and the voltage will be **𝟎°.**

**122 ** The dc applied voltage necessary for the same heating affect in the resistance will be**120 V.****Questions 123 to 124 refer to data given below:**

An a.c wave form with a frequency of 1.5 kHz has a peak value of 3.3 V.

**123 ** The instantaneous value of voltage at 0.65 micro-second will be **20.2 m**V

**124 ** The instantaneous value at 1.2 milli-seconds will be –**3.1 V.****Questions 125 to 128 refer to data given below:**

The circuit shown in figure below has a 60 Hz supply voltage with a maximum value

of **160 V.**

**125 ** The instantaneous current at 𝜋⁄4 radians will be **11.3 A**.

**126 ** The instantaneous power at 𝜋⁄4 radians will be** 2.56 kW.**

**127 ** The instantaneous value of current at5𝜋4radians will be –**5.5 A.**

**128** The instantaneous power at3𝜋4radians will be **2.56 kW.****Questions 129 to 132 refer to data given below:**

A 300 V sinusoidal ac supply is applied to a 50-ohm resistor.

**129** The peak value of current through the resistor will be **8.28 A.**

**30** The rms value of current through the resistor will be** 6 A.**

**131** The average value of current for the half cycle will be **5.4 A.**

**132** The power dissipated in the resistor will be** 1.8 kW.Questions 133 to 135 refer to data given below:**

A conducting loop rotated in the magnetic field has an axial length of 𝑙 = 30𝑐𝑚 and a

distance between sides of 𝐷 = 8𝑐𝑚. The flux density of the magnetic field is 𝐵 = 0.25

Tesla and the loop is rotated at 140 revolutions per minute.

**133** The output voltage will be **28 mV**.

**134 ** If the loops has10 turns instead of one the maximum output voltage will be **880 mV.**

**135** For the generator with 10 turns the instantaneous level of voltage at5𝜋4radians from

𝑒 = 0 will be –**0.62 V.**

**136 ** In the above case the value of output voltage at 25 ms from 𝑒 = 0 will be **315.4 mV.**

**Questions 137 to 139 refer to data given below:**

A sisusoidal waveform with an rms value of 6 V and a frequency of 30 Hz is applied across a 120Ω resistor.

**137 ** The instantaneous power dissipated in the resistor at 5.5 milli-seconds from the time that the waveform commences to grow positively from zero, will be** 0.44 W.**

**138 ** The peak instantaneous power dissipated in the resistor will be **6 W.**

**139** The average power dissipated in the resistor will be **0.3 W.**

**40 ** 90<33.7°×25.5<11.3°=**𝟐𝟐𝟗𝟓<**−22.4°.