Electrical Circuit Revision 1

One kilowatt-hour of energy is equivalent to  ____________.

• 3.6 x 10⁶  joules

• 1.44 x 10⁴ joules

• 6.9 x 10⁴ joules

• 2.4 x 10⁴ joules

The total equivalent resistance of a parallel circuit is always ____________.

• larger than that of a branch with the greatest resistance

• smaller than that of a branch with the greatest resistance

• equal to the sum of the individual branch resistance

• smaller than that of a branch with the lowest resistance

Which of the following statements best describes the application of Fleming's Left-Hand Rule?

• It is used to determine the direction of current flow in a conductor 1.5 A

• It is used to find the direction of magnetic field lines around a current-carrying          wire. 0.5 A

• It is used to predict the direction of force on a current-carrying conductor in a   magnetic field.

• It is used to calculate the resistance of a circuit.

When the current flow in a resistor is doubled, the power dissipated is ___________.

• halved

• same

• quadruple

• zero

The magnitude of the force acting on a current-carrying conductor is directly proportional to ____________________.

• flux density of the main magnetic field

• the current in the conductor

• the length of the conductor in the magnetic field

• all of these

An e.m.f. is induced in a conductor when it ____________________.

• stationary in a magnetic field

• moves across and cuts the line of flux

• moves in a parallel to the line of flux

• none of these

The basic unit of inductance is _____________.

• newton

• henry

• ohms

• tesla

A coil carrying a current of 0.25A has 200 turns. The mmf of the coil is ___________ Amphere-turns.

• 50

• 25

• 15

• 5

The symbol (dot) for the plan (or end) view of a conductor indicates ________

• no current flowing

• current flow towards the viewer

• current flow away from the viewer

• current is not moving

The value of current I is ___________ at junction B.

• I₁ + I₂ + I₃

• I₂ - I₃ - I₁

• I₁ - I₃ + I₂

• I₁ + I₃ - I₂