PPSC Physics Full Book With Answers

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PPSC Physics Full Book

Sr. # Questions Answers Choice
1 What is the range of values of power factor. 0 to -1 0 to +1 0 to 2 2 to 3
2 The time constant of a RL circuit is. L/R LR R/L L2/R
3 The unit of time constant RC is. Second second-1 Second -2 Second 2
4 The value of mutual inductance can be increased by Decreasing number of turns in the coil Increasing number of turns in the coil Winding the coil on china clay Winding the coil on wooden frame
5 In which of the following eddy current is not used Induction furnace Automobile speedometer Electromagnetic damping X- rays diffraction
6 Iron loss in a dynamo arises because of. The resistance of armature coil The production of eddy current The presence of mechanical friction The leakage of flux
7 The output of a generator which uses a split ring commutator is. sinusoidal A.C. wave Pulsating D.C. wave Constant D.C Voltage Linerly increasing voltage.
8 In the circult, the ammeter reading is 0.5 A . If the resistance of the voltmeter is 180Ohm What is the voltmeter rediang. 90 V 100 V 180 V 900 V
9 In an induction coil, the secondary emf is. Zero at the break of the circuit Zero during make of the circuit Very high during make of the circuit. Very high during break of the circuit
10 A generator running in reverse may be called as. A.C. Generator D.C. generator Motor Commutator
11 Which factor remains constant in a transformer. Current Voltage Power Frequency
12 If the transformer turns ratio is 2 and the impedance of primary coil is 250 Ohms then the impedance secondary coil will be. 125 Ohms 250 Ohms 500 Ohms 1000 Ohms
13 If the transformer turns ratio is 2 and the impedance eof primary coil is 250 Ohms then the impedance secondary coil will be. 125 Ohms 250 Ohms 500 Ohms 1000 Ohms
14 The long distance transmission of electrical energy is done at. High potential and low current High potential and highs current Low potential and high current Low potential and low current
15 Why does a transformer have a core made of iron. Iron has a high melting point Iron is a magnetic material Iron potential and high current Iron is a conductor of electricity
16 A step up transformer has a turn ratio of 1:100 A voltage of 20 V is connected across the primary coil What is the secondary voltage. 0.2 V 5 V 100 V 2000 V
17 A transformer is needed to convert a mains 240 V supply into a 12 V supply it there are 200 turns on the primary coil, how many turns should there be on the secondary coil. 100 200 400 600
18 The cause of production of eddy current is the Current flowing in a conductor Current flowing in a insulator Motion of a conductor in a varying magnetic field Motion of an insulator in a varying magnetic field
19 Eddy current can be minimized by Moving the conductor rapidly Moving the conductor slowly Using a metallic core Using a laminated core
20 A straight copper wire a moved in a uniform magnetic field such that it cuts the magnetic lines of force then. emf will not be induced emf will beinduced sometimes emf will be induced and sometimes not The number of turns iin the coil increases
21 A transformer is used to. Convert D.C. into A.C. Convert A.C. in to D.C. Obtain A.C. voltage Enhance the power
22 A device which converts electrical energy into mechanical energy is called. A.C generator D.C. generator Motor Commutator
23 In what form is the energy stored in an inductor. Magnetic electrostatic Magnetic and electrostatic All of the above
24 Under which of the following conditions current in a circuit is wattles. When inductance in the circuit is zero When resistance in the circuit is zero When current is alternating When resistance and inductance both are zero
25 The device in the circuit that consume electrical energy are known as. Resistors Capacitors Fuses Load
26 The core of a transfer is made of iron because Iron is a good electric material Iron is cheaper than copper Iron is easily magnetized and demagnetized Iron makes a good permanent magnet
27 Direct current generators use. Coiled rings Split rings slip rings solenoid rings
28 When a wire moves perpendicularly to a magnetic field, the induced emf does ot depends upon The velocity of the wire The resistance of the wire The flux density of the magnetic The orientation of the wire field
29 The direction of induced emf during electromagnetic induction can be determined by making use of. Faraday's law Ampere;s law Lenz's law Laplace law
30 On which principle the induction coil works on. Self induction Ampere's rule Mutual induction Gauss's law
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