10 Questions

Questions and Answers

- 1.In which direction does electric current flow around a circuit.
- A.
Clockwise

- B.
Anti-clockwise

- C.
Positive to Negative

- D.
Negative to Positive

- E.
Left to right

- 2.When an electric current flows through a wire what is moving?
- A.
Molecules move along the wire

- B.
Atoms move along the wire

- C.
Protons move along the wire

- D.
Electrons move along along the wire

- E.
Ions move along the wire

- 3.A current of 2.5A flows through a light bulb with a potential difference of 10V applied across it. What is the resistance of the light bulb?
- A.
0.25 ohms

- B.
4 ohms

- C.
7.5 ohms

- D.
12.5 ohms

- E.
25 ohms

- 4.A 60 ohm heater is used in a car heating system. If a potential difference of 12V is applied, what is the current that flows through the heater.
- A.
0.2A

- B.
5A

- C.
48A

- D.
72A

- E.
720A

- 5.
- A.
Its resistance increases if the voltage increases

- B.
Its resistance decreases if the voltage increases

- C.
Its resistance decreases if the current increases

- D.
Its resistance increases if the temperature increases

- E.
Its resistance decreases if the temperature increases

- 6.An electrical device that will only let the electric current flow in one direction is called
- A.
A Bulb

- B.
A Battery

- C.
An LDR

- D.
A Diode

- E.
A Termistor

- 7.Two resistors are connected in series. If the resistors are 20 ohms and 30 ohms the total resistance of the circuit is
- A.
0.67 ohms

- B.
1.5 ohms

- C.
10 ohms

- D.
50 ohms

- E.
600 ohms

- 8.A 10 ohm resistor and a 50 ohm resistor are connected in parallel. The best description of the combined resistance is
- A.
Less than 10 ohms

- B.
10 ohms

- C.
Between 10 ohms and 50 ohms

- D.
50 ohms

- E.
More than 50 ohms

- 9.In a parallel circuit the component with the largest resistance gets:-
- A.
The most potential difference

- B.
The least potential difference

- C.
The most current

- D.
The least current

- E.
All components get the same current

- 10.As the current through a filament light bulb, its resistance increases. The best reason for this is:-
- A.
The light gets brighter

- B.
The filament gets hotter

- C.
The potential difference increases

- D.
The current increases

- E.
The filament vibrates