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

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

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

3. 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

4. Internal resistance is the resistance offered by________________?

   A. source of EMF
   B. conductor
   C. resistor
   D. capacitor

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

   A. Zero
   B. 2
   C. 1
   D. Not definite

6. 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

7. The phase angle between the voltage and the current in an AC circuit consisting of a resistance is______________?

   A. Zero
   B. 45°
   C. 90°
   D. 180°

8. The deflection for 50 division of galvanometer is decreased to 25 divisions by shunt resistance of 12Ω. Galvanometer resistance is_____________?

   A. 18Ω
   B. 30Ω
   C. 24Ω
   D. 12Ω

9. Circuit which gives continuously varying potential is called _______________________?

   A. complex network
   B. wheat stone bridge
   C. potential divider
   D. all of above

10. 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