Tag: domestic and commercial circuit

Questions Related to domestic and commercial circuit

If the length of filament of a heater is reduced by  10%, the power of the heater will 

physics electrical circuits domestic electric circuits and safety precautions domestic and commercial circuit electric power

  1. increase by about 9%

  2. increase by about 11%

  3. increase by about 19%

  4. increase by about 10%

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Correct Option: D
Explanation:

$P=\dfrac { { V }^{ 2 } }{ R } \ R=\dfrac { \rho l }{ A } \ \therefore P=\dfrac { { V }^{ 2 }A }{ \rho l } $

$ \therefore P\alpha \dfrac { 1 }{ l } \quad $ [Keep in $\dfrac{v^2A}{\rho }$ constant]
$\therefore$ with reduction of $l$ by $10\%$ power will increase by $10\%$.

The wire having a red plastic covering is a 

physics electric current and circuit domestic electric circuits and safety precautions domestic and commercial circuit electric power

  1. live wire

  2. neutral wire

  3. earth wire

  4. none of these

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Correct Option: A
Explanation:

During wiring in our houses , we use the traditional concept of using red color wire as live , black as neutral and green for earth. These color codes are used to distinguish between live, neutral and earth wires, which is a standard coding of color nowadays.

$15   A$ current rating used for ________ appliances.

physics electric current and circuit domestic electric circuits and safety precautions domestic and commercial circuit electric power

  1. Low power rating

  2. High power rating

  3. Medium power rating

  4. All

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Correct Option: B
Explanation:

$15   A$ current rating is used for appliances with high power rating such as washing machines, geysers, air coolers etc.

Bulbs will produce more illumination when connected in

physics electric current and circuit domestic electric circuits and safety precautions domestic and commercial circuit electric power

  1. Series

  2. Parallel

  3. Both

  4. None

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Correct Option: B
Explanation:

When connected in parallel each bulb has maximum potential difference across it. So, bulb will show its maximum power.

The wire having a black plastic covering is a

physics electric current and circuit domestic electric circuits and safety precautions domestic and commercial circuit electric power

  1. live wire

  2. neutral wire

  3. earth wire

  4. none of these

Show answer
Correct Option: B
Explanation:

During wiring in our houses , we use the traditional concept of using red color wire as live , black as neutral and green for earth.These color codes are used to distinguish between live, neutral and earth. which is a standard way of coding of colors for electric connections.

According to new convention, earth wire is coded by

physics electric current and circuit domestic electric circuits and safety precautions domestic and commercial circuit electric power

  1. Green colour

  2. Black colour

  3. Red colour

  4. All

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Correct Option: A
Explanation:

According to new convention, live wire of codded by brown colour, neutral wire is coded by light blue colour whereas earth wire is coded by green and yellow colour.

All domestic electrical circuits are connected

physics electric current and circuit domestic electric circuits and safety precautions domestic and commercial circuit electric power

  1. In series

  2. In parallel

  3. Both

  4. None of these

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Correct Option: B
Explanation:

Electric circuits are connected parallely so that if there is problem in any circuit the other circuit does not get affected.

Neutral wire is usually insulated with

physics electric current and circuit domestic electric circuits and safety precautions domestic and commercial circuit electric power

  1. Red colour

  2. Brown colour

  3. Black colour

  4. Green colour

Show answer
Correct Option: C
Explanation:

Live wire has an insulation of red or brown colour. Neutral wire with an insulation of black or blue colour.