物理家居用電 DSE、CE 選擇題（第 4 頁）

31.

Four strings of light bulbs connected in parallel to an a.c. supply, each string with bulbs in series

A Christmas tree is illuminated with four strings of light bulbs. Each string has ten identical light bulbs connected in series as shown in the figure. If one light bulb suddenly burns out, which of the following will happen ?

32.

Three-pin plug with pins P, Q, R and a fuse, and a cable with wires X (Brown), Y (Blue) and Z (Green / yellow)

The diagram above shows a three-pin plug and the wires connected to it. To which of the pins should each of the wires $X$ , $Y$ and $Z$ be connected ?

$P$	$Q$	$R$
$Z$	$Y$	$X$
$Y$	$X$	$Z$
$Y$	$Z$	$X$
$Z$	$X$	$Y$

33.

Which of the following diagrams correctly shows the connection of the wires of an iron to the pins of a plug ? ( $L$ : Live, $N$ : Neutral, $E$ : Earth)

Four diagrams A to D showing different connections of the live, neutral and earth pins to an iron through a switch

34.

Label: operating voltage 220 V / 50 Hz, power 500 W

The diagram shows the label attached to a rice cooker. Which of the following statements is/are true when the cooker is working at its rated values ?

(1)The resistance of the cooker is

96.8\ \Omega

.

(2)The cooker draws a current of

4.4

A from the mains supply.

(3)The cooker consumes

1

kWh of electrical energy in

2

hours.

35.

Which of the following is NOT a correct unit for the corresponding physical quantity ?

	Physical quantity	Unit
	charge	coulomb
	current	ampere
	resistance	ohm
	voltage	joule

36.

For safety, the correct way of connecting the fuse and switch to electrical appliances should be

37.

Two light bulbs $A$ and $B$ of ratings ' $10$ W, $6$ V' and ' $5$ W, $6$ V' respectively are connected in series to a $6$ V battery. Which of the following is/are correct ?

(1)The resistance of

A

is smaller than that of

B

.

(2)The current through

A

is the same as that through

B

.

(3)

A

is brighter than

B

.

38.

Label: operating voltage 220 V / 50 Hz, power 1500 W, fuse rating 30 A

The diagram shows the label attached to an electric appliance. How much electrical energy is supplied to the appliance in $2$ hours ?

39.

A 3-pin plug is connected to a boiler of rating " $2000$ W, $200$ V". Which of the following statements is/are true ?

(1)A

5

A fuse should be used in the circuit.

(2)The fuse should be placed on the brown wire of the cable.

(3)The yellow and green wire of the cable should be connected to the earth pin.

40.

Three-pin plug with pins labelled X, Y and Z

In the three-pin plug as shown, $X$ , $Y$ and $Z$ are respectively connected to the

$X$	$Y$	$Z$
earth	neutral	live
earth	live	neutral
neutral	earth	live
neutral	live	earth