物理電路 DSE、CE 選擇題（第 2 頁）

11.

4 V battery in series with bulbs A and B

The figure shows two light bulbs $A$ and $B$ , which are connected in series. The voltages across $A$ and $B$ are $3$ V and $1$ V respectively. Which of the following statements is/are correct ?

(1)The resistance of

A

is greater than that of

B

.

(2)The current flowing through

A

is greater than that through

B

.

(3)

A

is dimmer than

B

.

12.

Battery V with a 12 ohm resistor in series with two 6 ohm resistors in parallel, an ammeter in one branch

In the above circuit, the reading of the ammeter is $0.3$ A. What is the voltage $V$ of the battery ?

13.

A cell fully discharges at a constant current $225$ mA in $10$ hours. If its average voltage is $1.2$ V, what is the estimated total energy stored in the cell ?

14.

Resistors 8 ohm and 2 ohm in series in parallel with 6 ohm and 4 ohm in series between X and Y

In the circuit shown, a voltage of $10$ V is applied across $XY$ . What is the current passing through the $8\ \Omega$ resistor ?

15.

Battery with 1 ohm and 5 ohm resistors in parallel in series with a 2 ohm resistor and an ammeter

If the ammeter in the above circuit reads $3$ A, what is the voltage of the battery ?

16.

The voltage and the capacity of the cell of a portable music player are $3.6$ V and $700$ mA h respectively. The continuous playing time of the player is $15$ hours. The capacity $700$ mA h indicates the quantity of electric charges that the cell will discharge in $15$ hours of playing. Assume that the voltage remains constant during discharge, what is the estimated power of the player when it is playing ?

17.

In the following circuit, three identical light bulbs are connected to a cell. Under what conditions will light bulb $P$ have the maximum brightness ?

Cell and resistor with bulb and switch X in one branch and, in parallel, bulb with switch Y in parallel with bulb P

	Switch $X$	Switch $Y$
	open	closed
	open	open
	closed	closed
	closed	open

18.

Pictorial circuit with battery, ammeter, voltmeter, rheostat and a resistance wire AB with a crocodile clip

A student sets up the above circuit to study the effect of the length of a resistance wire on its resistance. As the crocodile clip is moved from $A$ to $B$ along the resistance wire, which of the following statements is/are correct ?

(1)The reading of the ammeter increases.

(2)The reading of the voltmeter increases.

(3)The voltmeter reading is directly proportional to the reading of the ammeter.

19.

Simple circuit with a resistor and a cell, point X marked on the wire

If the current in the circuit shown is $0.8$ A, what is the number of electrons passing the point $X$ in $1$ minute ?

20.

Cell with bulb X in series with bulbs Z and Y in parallel

Three identical light bulbs are connected to a cell as shown in the diagram. After some time, the filament of bulb $Z$ breaks. What will happen to the brightness of the remaining light bulbs ?

	Brightness of $X$	Brightness of $Y$
	increases	increases
	increases	decreases
	decreases	increases
	decreases	decreases