Diodes and bulbs, which bulbs is lighted up when switch S is open and closed

Answer: Option B

Basic Concepts on DC Circuit – river system

The ‘D.C.’ here mean direct current. It means that the current flows in one direction in the circuit.

The direction of the direct current refers to the conventional current, and it flows out of the positive (+) terminal of the cell / battery, around the circuit and flows back into the negative (-) terminal.

[Note: the direction of the electron flow is opposite to the conventional current]

To understand DC circuit, it will be useful to relate to a river system. Refer to the 3 videos below to learn more about 01: DC circuit similar to river system, 02: Series Circuit 03: Parallel Circuit and 04: Combined Circuit.

01: How is DC circuit related to a river system

02: Series Circuit

03: Parallel Circuit

04: Combined Circuit (Series and Parallel)

Now, after you have the basic concepts and rules for the circuits, let’s look at some simple example to reinforce you understanding.

Example 01: Series Circuit

Example 02: Parallel Circuit

Example 03: Combined Circuit

Example 04: PP2012P2Q7 DC circuit : pd across 2 points on two separate branches.

Hope these series of videos help in you understanding of DC circuit.

DC Circuit is just like a River System!

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Cells in parallel vs single cell

Answer: Option C

Potential Divider Summary

Rules of Series and Parallel Circuits

Rules of Series and Parallel Circuits

To understand direct current (DC) circuits, the best way is to think in terms of river system.

Series Circuit

Parallel Circuit

Series and Parallel Circuit

 

Examples:

DC Circuit Calculations

Solutions: Option A