Physics ECAT Pre Engineering MCQ's Test For Full Book With Answers

Physics ECAT Pre Engineering MCQ's Test For Full Book

Sr. # Questions Answers Choice
1 The power dissipation in a pure inductive or capacitance circuit is maximum positive zero none
2 The ratio of the r.m.s value of the applied voltage to the r.m.s value of resulting a.c. is Impedance Inductance Reactance Resistance
3 Such an inductor coil which does not consume energy and is often employed for controlling a.c. without consumption of energy is called Choke impedance Semi-conductor None
4 Units of impedance are Henry Ohms moh Watt
5 The combined effect of resistance and reactance in a.c. circuit is called conductance resistance impedance choke
6 The reactance of a cell changes directly with frequency of a.c the inductance both a and b none of these
7 Current varies with voltage Inversely as square root Directly None of these
8 The basic circuit element in a d.c. circuit is a/an Inductor Resistor Capacitor Battery
9 The average value of current and voltage over a cycle is Positive Negative Zero May be positive or negative
10 The phase at the positive peak is <span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Π/2</b></span> <span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Π</b></span> 3<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Π/2</b></span> 2<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Π</b></span>
11 The r.m.s value of a.c. current is always positive negative zero all of these
12 The sum of positive and negative peak values are usually written as P-P value negative zero may be positive or negative
13 The highest value reached by voltage or current in one cycle is called root means square value peak value peak to peak value instantaneous value
14 The angle which specifies the instantaneous value of the alternating voltage or current is called phase critical angle angle of incidence all of these
15 The root mean square voltage for alternating current is All of these
16 The peak value of alternating voltage is given by
17 The current in LCR circuit will be maximum whenωis As large as possible Equal to natural frequency of LCR system
18 Alternating current can not be measured by D.C. ammeter because A.C. can not pass through D.C. Ammeter A.C. changes direction Average value of current for complete cycle is zero D.C. Ammeter will get damaged
19 The value of current at resonance in series LCR circuit is affected by the value R only C only L only R, C and L
20 A circuit has a resistance of 11Ωan inductive reactance of 25Ωand a capacitance reactance of 18Ω. It is connected to an a.c. source of 200 V and 50 Hz. The current through the circuit (in amperes) is 11 15 18 20
21 In LCR circuit which one of the following statement is correct? L and R oppose each other R value increase with frequency The inductive reactance increases with frequency The capacitive reactance increases with frequency
22 A fuse wire is having 5 ampere current rating. What is the peak value of current it can have? 0.7074 A 7.07 A 0.0707 A 7.707 A
23 An L-R circuit has R = 10 Ω and L = 2 H. If 120 V, 60 Hz A.C. voltage is applied, then current in the circuit will be 0.32 A 0.16 A 0.48 A 0.80 A
24 In and A.C. circuit, the current lags behind the emf. The power factor is 50% In order to make it 100%, What additional component is to be used? Impedance Inductance Capacitance Resistance
25 The henry is the unit for Resistance Magnetic flux Magnetic field Inductance
26 Energy is stored in the choke coil in the form of Heat Magnetic energy Electric energy Electro-magnetic energy
27 The reactance of a coil when used in the domestic A.C. power supply (220 volts, 50 cycles per second) is 50 ohms. The inductance of the coil is nearly 2.2 henry 1.6 henry 0.22 henry 0.16 henry
28 In a capacitive circuit Current leads voltage by phase of<i style="box-sizing: border-box; color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 19.8px;">π</i><span style="box-sizing: border-box; color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 19.8px;">/2</span> Voltage leads current by phase of<i style="font-family: &quot;Times New Roman&quot;; font-size: 19.8px; color: rgb(34, 34, 34); box-sizing: border-box;">π</i><span style="font-family: &quot;Times New Roman&quot;; font-size: 19.8px; color: rgb(34, 34, 34); box-sizing: border-box;">/2</span> Current and voltage are in same phase Sometime current and sometime voltage leads
29 The peak voltage in a 220 volt A.C. supply is nearly 220 volt 253 volt .311 volt 440 volt
30 An ideal choke (used along with fluorescent tube) would be A pure resistor A pure capacitor A pure inductor A combination of an inductor and a capacitor
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