AC Fundamentals Objectives Part 05
81 Power factor of an inductive circuit can be improved by connecting a capacitor to it in
82 For the same load, if the power factor of load is reduced, it will draw more current.
83 For the saw tooth current waveform, the rms value is 5.77A.
84 The effects due to electric current are I. Magnetic effect, II. Heating effect, III.
Luminous effect. Appliance working on which effect can be used on ac as well as dc
supply? II. and III. Only.
85 The rms value of the waveform shown in Fig.14 will be 57.7.
86 The effects due to electric current are I. Thermal effect, II. Luminous effect, III.
Chemical effect, IIII. Magnetic effect. Which two effects are significant when current
flows through transmission lines I and IV only.
87 A current in ac circuit measures 4 A. Then , the maximum instantaneous magnitude of
this current will be 𝟒 × √𝟐 A.
88 The equation of an a.c voltage is 𝑉 = 200 sin 50𝜋𝑡. Then, the r.m.s value of voltage is
𝟏𝟎𝟎√𝟐 V. ??
89 When a.c. current flows through a resistance, then current and e.m.f. are in phase.
90 The power factor of incandescent bulb is unity.
91 A incandescent bulb can work on both ac as well as dc.
92 It is know that a given capacitor will fail if the terminal voltage exceeds 180 V. If the
circuit is operating on sinusoidal steady voltage, the maximum rms voltage that may
applied to the capacitor will be 127 V.
93 For an alternating voltage form factor is𝐑𝐌𝐒 𝐕𝐚𝐥𝐮𝐞𝐌𝐞𝐚𝐧 𝐯𝐚𝐥𝐮𝐞
94 In and a.c. circuit, the current any of the above, depending upon the elements (L,C
or R) of the circuit.
95 Power factor of the magnetizing component of a transformer is zero.
96 Which of the following statement is not necessarily valid for ac currents: Alternating
currents is suitable of charging batteries.
Questions 97 and 98 refer to the data given below:
A current is given by 𝑖 = 45.24 sin 377𝑡.
97 The maximum value of the current is 45.24 A.
98 The frequency is𝟑𝟕𝟕𝟐𝝅Hz.
99 A circuit has impedance of (3 + 𝑗4). If a voltage (100 + 𝑗50) is applied, the power in
the circuit will be 500 W.
100 Which will draw least current 40W lamp.
Questions 101 and 102 refer to the given data below: