PPSC Physics Chapter 6 Electricity and Magnetism With Answers

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PPSC Physics Chapter 6 Electricity and Magnetism

Sr. # Questions Answers Choice
1 A pure capacitor is connected in an AC circuit The power factor of the circuit will be. Unity Infinity 0.5 Zero
2 What is the power factors of wattles current. Infinity Unity 0.5 Zero
3 The source of magnetic field are Isolated magnetic poles Electric charge distributions Current loops Solenoids
4 When the number of turns in the solenoid is doubled without any change in teh length of the solenoid its self inductance will be. Halved Doubled 4 times 8 times
5 The inductance in a coil plays the same role as Inertia plays in machans torque plays in machines Energy plays in machines Momentum plays in machines
6 By placing soft iron inside a coil Increases the magnetic flux Decreases the magnetic flux Creates no change in magnetic flux Decreases the diameter of the core
7 The magnetic flux linked with a circuit when a unit current flows through it is known as. Induced current Induced emf Coefficient of self induction of circuit Eddy current
8 The main causes of power losses in a generator are. Pulsatng current Eddy current Magnetic current Both B and C
9 Self inductances of solenoid is Directly proportional to the current flowing through the wire Directly proportional to its length Inversely proportional to area of corss section Directly proportional to number of turns
10 The sensitiveness of a moving soil galvanometer can be increased by Decreasing the number of turns of the coil Decreasing the area of the coil Increasing the couple per unit twist of the suspension Increasing the magnetic flux
11 The mains frequency in Pakistan is 20 Hz 50 Hz 40 Hz 60 Hz
12 How the fuse wire in electric supply line is connected to protect the electrical appliances. In parallel In sereis In mixed order In vertical position
13 How the small bulbs used for decoration purposes are connected. In parallel In series In mixed order In vertical position
14 What is the range of values of power factor. 0 to -1 0 to +1 0 to 2 2 to 3
15 The time constant of a RL circuit is. L/R LR R/L L2/R
16 The unit of time constant RC is. Second second-1 Second -2 Second 2
17 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
18 In which of the following eddy current is not used Induction furnace Automobile speedometer Electromagnetic damping X- rays diffraction
19 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
20 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.
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