ECAT Physics Online Test With Answers

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ECAT Physics Online Test

Sr. # Questions Answers Choice
1 The magnitude of alternative voltage V: Always increase Always decrease Remains constant Does not remain constant None of these
2 If we connected the ordinary DC ammeter to measure alternating current, it would measure its: Instantaneous value RMS value Value averaged over a cycle Either (B) or (C) Either (A) or (C)
3 The RMS value of alternating current is: 0.7 times at the peak value 0.5 times the peak value 0.7 times the Instantaneous value Equal to maximum voltage None of these
4 The Instantaneous value of alternative current maybe: The same as its RMS value Greater than its Rms value The same as its peak value Any of these None of these
5 Peak value of alternative current is:
 one of its Instantaneous value Equal to its RMS value The same as its peak-to-peak value Both (B) and (C) None of these
6 The sum of positive and negative peak values is called: Instantaneous value Peak value Rms valuie Peak-to peak-value None of these
7 The highest value reached by the voltage or current: In quarter cycle is called Instantaneous value In half cycle is called peak-to-peak value In one cycle is called peak value In half cycle is called Instantaneous value None of these
8 The entire wave form of sinusoidal voltage is actually a set of all the: Positive maximum value + V<sub>o</sub>and negative maximum value -V<sub>o</sub> Posiotive maximum value +V<sub>o </sub>and zero Zero and negative maximum value -V<sub>o</sub> Any of these None of these
9 The waveform of alternating voltage is a: Square Rectangular Saw-tooth Sinusoidal None of these
10 The wave form of alternating voltage is the graph between: Voltage across X-axis and time across y-axis Current and time Voltage along y-axis and time along x-axis Voltage and current Either (B) or (D)
11 The most common source of alternating voltage is: Motor Transformer AC genrator Both (A) and (C) Both (A) and (B)
12 The time interval during which the Voltage source changes its polarity once is known as: Time period T Half the time period Quarter the time period Two third of the time period None of these
13 Nowadays, Most of the electric energy is produced by the A.C. generators using: Hydal water Geothermal energy Solar energy Biomass Both (B) and (D)
14 Alternating current is produced by a voltage source which polarity: Remains the same Reverse after period T Keeps on reversing with time Reverse after every time interval T/2 Both (C) and (D)
15 Alternating current can be transmitted: To long distance At very high cost At very low cost Both (A) and (C) Both (A) and (B)
16 The direction of induced current is always so as to oppose the cause which produces it. This is Lenz's law Ampere's law Faraday's law Coulomb's law None of these
17 Faraday's law of electromagnetic induction has been used in the construction of: Galvanometer Voltmeter Electric motor Electric genrator Commutator
18 The law of electromagnetic induction is related to: Coulomb Ampere Faraday Lenz None of these
19 The rate change of area expressed is expressed in: None of these ms<sup>-1</sup> m<sup>2</sup>s<sup>-2</sup> ms<sup>-2</sup> m<sup>2</sup>s<sup>-1</sup>
20 Plan of a coil makes an angle of 20º with the lines of magnetic field. The angle between B and vector area of plane of coil is:

 Also 20<span style="font-family: &quot;Times New Roman&quot;, serif; font-size: 12pt; text-align: justify;">º</span><p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt; line-height:107%;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;"><o:p></o:p></span></p> 70<span style="font-family: &quot;Times New Roman&quot;, serif; font-size: 12pt; text-align: justify;">º</span><p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt; line-height:107%;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;"><o:p></o:p></span></p> 90<span style="font-family: &quot;Times New Roman&quot;, serif; font-size: 12pt; text-align: justify;">º</span><p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt; line-height:107%;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;"><o:p></o:p></span></p> 180<span style="font-family: &quot;Times New Roman&quot;, serif; font-size: 12pt; text-align: justify;">º</span><p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt; line-height:107%;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;"><o:p></o:p></span></p> None of these
21 A square loop of wire is moving through a uniform magnetic field. The normal to the loop is oriented parallel to the magnetic field. The emf induced in the loop is: Zero Of smaller magnitude Of larger magnitude Sometimes B, sometimes C Neither of these
22 A metal road of length 1m is moving at a speed of 1 ms-1In a direction making angle of 30º with 0.5 Y magnetic field. The emf produced in the rod is:

 0.25 N 0.25 V 2.5 V 2.5 N 25 V
23 Motional emf is called motional: Electromagnetic force and is measured in newtons Electromotive force and is measured in volt Electromotive force and is measured in newtons Electromagnetic force and is measured in volts None of these
24 When the conductor moved across a magnetic field: Emf induced is similar to that of a battery<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt; line-height:107%;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;"><o:p></o:p></span></p> Emf induced gives rise to induced current<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt; line-height:107%;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;"><o:p></o:p></span></p> An emf induced across its ends<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt; line-height:107%;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;"><o:p></o:p></span></p> All are correct<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt; line-height:107%;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;"><o:p></o:p></span></p> None of these<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt; line-height:107%;font-family:&quot;Times New Roman&quot;,&quot;serif&quot;"><o:p></o:p></span></p>
25 A coil of constant area is placed in a constant magnetic field. An include current is produced in the coil when: The coil is destroyed The coil is Rotated The coil is neither destroyed nor rotated Both (A) and (B) None of these
26 The magnitude of induced emf depends upon the: Rate of decrease of magnetic field Rate of change of magnetic field Rate of increase of magnetic flux Constancy of magnetic field None of these
27 In magnet-coil experiment, emf can be produced by: Keeping the coil stationary and moving the magnet Keeping the magnet stationary and moving the coil Relative motion of the loop and magnet Any one of above All above
28 The induced current in the loop can be increased by: Using a stronger magnetic field Moving the loop faster Replacing the loop by a coil of many turns All above Both (A) and (B)
29 The induced current is a conductor depends upon: Resistance of the loop Speed with which the conductor moves Any of these Both (A) and (B) None of these
30 The phenomenon of generation of induced emf is called Electrostatic induction Magnetic induction Electromagnetic induction Electric induction Both (A) and (D)
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