phy_4.2.4_Series and parallel circuits 串聯及並聯電路

如圖所示，利用一個安培計量度流經電阻器 R 的電流。電源的電壓為 6 V。假如安培計的讀數為 3 A，R 的電阻值是多少？

An ammeter is used to measure the current through a resistor R as shown. The voltage of the supply is 6 V. The ammeter reads 3 A. What is the resistance of R?

• 0.5 Ω

• 1.0 Ω

• 1.5 Ω

• 2.0 Ω

當三個電阻器如圖般接駁時，它們的等效電阻是 30 Ω。求電阻值 R。

The combination of three resistors as shown has an equivalent resistance of 30 Ω. Find resistance R.

• 5 Ω

• 10 Ω

• 20 Ω

• 30 Ω

在圖中的電路中，流經 3 Ω 電阻器的電流是 4 A。求 A 和 B 兩點之間的電勢差。

In the circuit as shown, the current flowing through the 3 Ω resistor is 4 A. What is the potential difference between A and B?

• 0.8 V

• 1.25 V

• 12 V

• 20 V

在圖中的電路中，1 Ω 電阻器兩端的電壓是多少？

What is the voltage across the 1 Ω resistor in the circuit shown?

• 1.0 V

• 2.0 V

• 3.0 V

• 4.0 V

如圖所示，兩個相同的燈泡 X 和 Y 接駁至一組電池和一個安培計上。兩個燈泡的等效電阻為 2 Ω，而安培計的讀數為 2 A。燈泡 X 兩端的電壓是多少？

Two identical light bulbs X and Y are connected to a battery and an ammeter as shown. The equivalent resistance of the light bulbs is 2 Ω and the ammeter reads 2 A. What is the voltage across light bulb X?

• 0.5 V

• 1 V

• 2 V

• 4 V

三個電阻器如圖般接駁至一組電池上。假如通過 6 Ω 電阻器的電流為 1.6 A，A 和 B 兩點之間的電壓是多少？

Three resistors are connected to a battery as shown. The current flowing through the 6 Ω resistor is 1.6 A. What is the voltage across A and B?

• 4.8 V

• 9.6 V

• 14.4 V

• 24 V

如圖所示，把四個完全相同的電阻器連接至電池組。求 A 點與 B 點兩端的電勢差。

Four identical resistors are connected to a battery as shown. Find the potential difference across points A and B in the above circuit.

• 1.5 V

• 3 V

• 4.5 V

• 6 V

下圖所示的為某電路的其中一部分。假如 V₁ 的讀數為 2.0 V，V₂ 的讀數是多少？

The figure below shows part of a circuit. If the reading of V₁ is 2.0 V, what is the reading of V₂?

• 0.8 V

• 2.5 V

• 5.0 V

• 無法計算

  It cannot be determined.

如圖所示，兩個完全相同的燈泡接駁至一組 3 V 的電池上。如果燈泡 P 的電阻值為 6 Ω，求流經燈泡 Q 的電流。

Two identical filament lamps are connected to a 3 V battery as shown. If the resistance of lamp P is 6 Ω, find the current flowing through Q.

• 0.25 A

• 0.50 A

• 0.75 A

• 1.00 A

如圖所示，兩個電阻器 $R_1$ 和 $R_2$ 連接至一個電池組。流經 $R_1$ 和 $R_2$ 的電流分別為 $I_1$ 和 $I_2$ 。 $R_2$ 的電阻可寫成為
Two resistors  $R_1$ and $R_2$ are connected to a battery as shown. The current through $R_1$ and $R_2$ are $I_1$  and  $I_2$ respectively. The resistance of $R_2$  can be expressed as

•  $R_1$ 

•  $\frac{I_1R_1}{I_2}$  

•  $\frac{I_2R_1}{I_1}$  

•  $\frac{I_2}{I_1R_1}$