Tag: domestic electric circuits and safety precautions

Quizzes (0) Questions (98)

Questions Related to domestic electric circuits and safety precautions

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

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

  1. increase by about 9%

  2. increase by about 11%

  3. increase by about 19%

  4. increase by about 10%
Reveal answer Fill a bubble to check yourself
D Correct answer
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 $10\%$.

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

The wire having a red plastic covering is a 

  1. live wire

  2. neutral wire

  3. earth wire

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

The wire having a black plastic covering is a

  1. live wire

  2. neutral wire

  3. earth wire

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
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.