 ### 10 Multiple Choice Direct Current Circuit Exercises and Their Discussion Pembahasan

Examples of Multiple Choice Direct Current Circuit Questions and Discussion with Answer Keys Direct current is the flow of electrons from a point of high potential energy to another point of lower potential energy.

Sources of direct current are usually batteries (including batteries and Voltaic Elements) and solar panels. Direct current usually flows in a conductor, although it is possible for direct current to flow in semi-conductors, insulators, and vacuums.

This time our team will share 10 sample questions and discussions of DC circuits from various 12th grade physics book publishers for you to study at home in preparation for the National Examination or Daily Examination.

Daftar Isi

## 1 – 5 Electric Current Circuit Problems for Class 12 SMA

1. The figure below shows a direct current circuit. The resistance is r is … ohm

2. The picture below shows a direct current circuit, the resistance in r is … ohm

3. In the circuit diagram below, the current through R and the voltage across the ends of R are…

4. Which statement is true about the process of discharging a battery in which sulfuric acid is the electrolyte?

a. The two PbO . electrodes2 and Pb turns into PbO3O4

b. The two PbO . electrodes2 and Pb turns into PbO3

c. The two PbO . electrodes2 and Pb changed to PbSO4

d. Both electrodes change Pb as anode PbOnoda2 as cathode

e. Both electrodes change Pb as cathode PbO2 as anode

#### Discussion

The Process of Discharging the Battery / When the Battery is Used

In this process, there is a change in chemical energy into electricity and changes occur in the anode, cathode, and electrolyte solution. At the anode, the original lead dioxide (PbO2) becomes lead sulfate (PbSO4). At the cathode, the original pure lead (Pb) became lead sulfate (PbSO4). In the electrolyte solution, sulfuric acid (H2SO4) will become dilute because water is formed.

5. An incandescent light bulb when installed turns red. After examining it, it was found that on the lamp it was written 60W;220V, while the existing voltage is 110 volt.

If I is the current intensity of the light at a distance of 2 m and I0 is the intensity when the mains voltage is 220 volt, also at a distance of 2 m and the resistance of the lamp is fixed, then I : I0 is…

A.

B

C. 1/8

D. 1/16

E. 1/32

Discussion:

The intensity of light is directly proportional to the power of light and also proportional to the square of the voltage.

### 6 – 10 Direct Current Circuit Problems and Discussion

6. The factors that determine the specific resistance of a metal wire are

1) wire length

2) wire temperature

3) cross-sectional area of ​​wire

4) wire material

the correct statement is…

A. 1, 2 and 3

B. 1, 2, 3 and 4

C. 1 and 3

D. 2 and 4

E. 4 only

Discussion:

The resistance of the type of wire symbolized by is a predetermined constant based on the type of metal used to make the wire at a certain temperature (20 °C).

The resistance of the wire is related to the resistance of the wire as a conductor, according to the following equation.

R = xl/A

Information,

R = Electrical Resistance of the wire (J)

= resistance of wire (Ωm)

l = length of wire (m)

A = Cross-sectional area of ​​the wire (m²)

Thus, it can be seen that the things that affect the resistance of the wire as a conductor are the type of wire, the length of the wire and the cross-sectional area of ​​the wire.

7. If resistor R and capacitor C are installed in parallel then we connect the ends to the positive and negative poles of a battery, then in a stationary state…

(1) R gets hot

(2) C gets hot

(3) the current in R is fixed

(4) the charge at C changes with time

A. 1, 2 and 3

B. 1, and 3

C. 1 , 2, 3 and 4

D. 2 and 4

E. 4 only

Answer: 1 and 3 are correct (B)

Discussion

Capacitor C cannot conduct direct current and only flows through R (resistor) so that R will experience heat and the value of R will remain the same.

8. For an electric circuit as shown in the figure, the energy generated per second on resistance 2 is … W

9. In the electrical circuit below, the external resistance R is variable. The electric power at the external resistance R will be maximum if:

10. An electric lamp with 220V and 50W specifications is connected in series with a 1000 ohm electrical resistance, then mounted on a 110V mains voltage. This means that the electric current flowing in the circuit is … mA

A. 56

B. 84

C. 112

D. 234

E. 548