At resonance the value of the power factor in an L-C-R series circuit is_______________?

Related Mcqs:

1. An A.C series circuit containing 4Ω resistance and 3Ω inductive reactance. The impedance of the circuit is______________?

   A. 1Ω
   B. 5Ω
   C. 7Ω
   D. 7Ω

2. n an LCR series circuit, if V is the effective value of the applied voltage VR is the voltage across R VL is the effective voltage across L & Vc is the effective voltage across C then_______________?

   IA. V = VR+VL+VC
   B. V2 = VR2+VL2+VC2
   C. V2 = VR2+(VL-VC)2
   D. V2 = VL2+(VR-VC)2

3. Three equal resistors connected in series with a source of e m f together dissipate 10 W of power each. What will be the power dissipated if the same resistors are connected in parallel across the same source of e m f ?

   A. 40 W
   B. 90W
   C. 100W
   D. 120W

4. If capacitance of L-C circuit is made four times then frequency of the circuit becomes___________________?

   A. Twice
   B. One half
   C. Four times
   D. None

5. Why should a resistance be introduced in a circuit in series deliberately ?

   A. to increase current
   B. to decrease current
   C. to control current
   D. just to give a good look to circuit

6. A fuse is placed in series with the circuit to protect against__________________?

   A. high power
   B. high voltage
   C. high current
   D. over heating

7. The sharpness of resonance is__________________?

   A. Directly proportional to the damping force
   B. Inversely proportional to the damping force
   C. Equal to the square of damping force
   D. Equal to the square of damping force

8. Which one does not work according to resonance ?

   A. T.V
   B. Radio
   C. Microwave oven
   D. Bulb

9. Electrical resonance is observed in_______________?

   A. Radio
   B. Microwave oven
   C. Both in radio and microwave oven
   D. Neither in radio nor in a microwave oven

10. The energy absorbed by a body is __________________ at resonance?

    A. Maximum as well minimum
    B. Minimum only
    C. Maximum only
    D. 0