3rd year final

Which graph represents the correct relation between the electric potential difference (V) across the two terminals of the fixed resistance (R) and the ammeter reading (I) at the same temperature ?

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The figure illustrates a closed electric circuit when the switch (K) is opened so ................?

• The ammeter reading decreases , while the voltmeter reading increases

• The ammeter reading increases, while the voltmeter reading decreases

• The reading of both ammeter and voltmeter decreases

• The reading of both ammeter and voltmeter increases

The figure represents a part from a closed electric circuit. The equivalent resistance of the shown combination equals ..................?

• R

• 2 R

• R/2

• 3 R/5

The figure represents lwo straight current carrying parallel wires (A) and (C) which of the following choices represents the intensity and the direction of the current in wire (C) that produces a neutral point at point (Z) ?

• 2 A , in the same direction of the current in wire (A)

• 0.5 A , in the same direction of the current in wire (A)

• 0.5 A , in opposite direction of the current in wire (A)

• 2 A , in opposite direction of the current in wire (A)

The graph represents the relation between the magnetic flux density (B) at the mid-point of the axis of a number of spiral coils (L,M,N and O) and the current intensity (I) passing through them, if you know that all the coils have the same number of turns and their cores have the same magnetic permeability, then the coil that has the smallest length is coil .................?

• N

• L

• M

• O

Using the illustrated in both figures (1) and (2) . Which of the following relations represent correctly the relation between magnetic flux density (B) at points C₁ and C₂ ?

• 2.5 A, upward

• 2.5 A, downward

• 25 A, downward

• 25 A, upward