# Objective Type Question or MCQ of Electrical Circuits and Magnetic Fields page-4

46. The transient currents are associated with the

a) Applied voltage to the circuit
b) Changes in the stored energy in the inductors and capacitors
c) Resistance of the circuit
d) Impedance of the circuit

Ans: (b)

47. The double energy transients occur in the

a) R-L circuit
b) R-C circuit
c) Pure inductive circuit
d) R-L-C circuit

Ans: (d)

48. A closed switch has a resistance of

a) Infinity
b) Zero
d) About 50 ohms at room temperature

Ans: (b)

49. The ionization current in the liquids and gases results from

a) Protons
b) Electrons
c) Neutrons
d) Positive or negative or negative ions

Ans: (d)

50. Two 500 ohms, 1 watt resistors are connected in parallel. Their combined resistance and wattage rating will be

a) 5000 ohms, 1 watt
b) 250 ohms, 2 watts
c) 1000 ohms, 2 watts
d) 500 ohms, 2 watts

Ans: (b)

51. A resistor is connected across a 45 volt battery to provides 13 mA of current. The required resistance with suitable wattage rating will be

a) 4.5 ohms, 1 watt
b) 45 ohms, 10 watts
c) 1000 ohms, 2 watts
d) 45,000 ohms, 1/3 watt

Ans: (d)

52. A 2.2 lead acid cell

a) Is a primary cell
b) Is a secondary cell
c) Has unlimited shelf life
d) Has a maximum current rating of about 150 mA

Ans: (b)

53. The formation of the hydrogen bubbles around the carbon electrode in a dry cell is

a) Local action caused by chemical impurities
b) Polarization caused by electrolysis
c) Depolarization caused by manganese dioxide
d) An advantage because it increases the voltage output

Ans: (b)

54. When a lead acid battery is charged

a) The battery voltage must be more than charging voltage
b) Connect the positive battery terminal to the negative on the charging current
c) The charging current must flow in same direction as the discharging current
d) Connect negative to negative and positive to positive

Ans: (d)

55. The Edison cell

a) Is a primary cell
b) Uses sulphuric acid electrolyte
c) Has 2.5 volts output
d) Has nickel and iron electrolyte

Ans: (d)

56. The cells are connected in series to

a) Increase the current output
b) Increase the voltage output
c) Decrease the internal resistance
d) Decrease the amount of charging voltage required

Ans: (b)

57. A 45-volt source with an internal resistance of 2 ohms is connected across a wire-wound resistor. The maximum power will be dissipated in the resistor when its resistance equals

a) Zero
b) Ohms
c) 45 ohms
d) Infinity

Ans: (b)

58. A magnet can pick up nail because of

a) Excess charge on the nail
b) Magnetic induction
c) Declination of magnetic field
d) Molecular magnets in the air around the nail

Ans: (b)

59. A magnetic compass point to the

a) Geographical poles
b) True north pole
c) Magnetic north pole
d) Agonic line of the earth filed

Ans: (c)

60. If the wire which is vertical to this page has electron flow downward the conductor will have

a) No magnetic field
b) A counter-clockwise field in the plane of the power
c) A clockwise field in the plane of the paper
d) A counter-clockwise field in the plane perpendicular to the paper

Ans: (b)