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Multiple choice physics effects of electric current joule's law of heating thermal effect of electric current heating effect of electric current

 When electric current is passed through conductor i.e. generates heat due to resistance it offers to current flow. What this phenomena known as :

  1. Burning effect of electricity

  2. Potential Effect of electricity

  3. Heating effect of electricity

  4. Floating effect of electricity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The phenomenon of generating heat due to the resistance of the conductor when a current passes through it is known as heating effect of electricity.

Heat produced     $H = I^2Rt$

Multiple choice physics effects of electric current joule's law of heating thermal effect of electric current heating effect of electric current

Which of the following terms does not represent electrical power in a circuit?

  1. $I^2R$

  2. $IR^2$

  3. $VI$

  4. $V^2/R$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$P=VI\quad .............(i)$

Hence, option (c) represents power.
$V=IR\quad .............(ii)$

From (i) and (ii),
$P=I^2R$
$P=V^2/R$
Hence, option (a) and (d )represents power too.
Option (b) does not represent power.

Multiple choice physics effects of electric current joule's law of heating thermal effect of electric current heating effect of electric current

A $1000\Omega$ electric iron is connected to $200v$, $50Hz$ ac source. Calculate average power delivered to iron, peak power and energy spent in one minute?

  1. $400W,\ 800W,\ 12\times 10^{5}\ J$

  2. $400W,\ 900W,\ 1.2\times 10^{5}\ J$

  3. $500W,\ 800W,\ 6\times 10^{5}\ J$

  4. $400W,\ 900W,\ 60\times 10^{5}\ J$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice physics effects of electric current joule's law of heating thermal effect of electric current heating effect of electric current

Which of the following statement is correct?

  1. seebeck effect is irreversible.

  2. Thomson effect is localised at the junction.

  3. Joule heating effect is indeoendent of the direction of flow of current in a conductor.

  4. Thomson effect is similer in origin to pelteir effect. They both are due to non-uniform distribution of electrons in a metal.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Joule heating (also referred to as resistive or ohmic heating) describes the process where the energy of an electric current is converted into heat as it flows through a resistance.

In particular, when the electric current flows through a solid or liquid with finite conductivity, electric energy is converted to heat through resistive losses in the material. The heat is generated on the microscale when the conduction electrons transfer energy to the conductor's atoms by way of collisions. It does not depend upon the direction of flow of current, but its amount.

Multiple choice physics effects of electric current joule's law of heating thermal effect of electric current heating effect of electric current

An electric iron draws a current of 15 A from a 220 V supply, What is the cost of using iron for 30 min everyday for 15 days if the cost of unit (1 unit =1 kWhr) is 2 rupees ? 

  1. Rs 49.5

  2. Rs 60

  3. Rs 40

  4. Rs 10
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

As we know that power(P)=v$\times$I
so P=15$\times$220=3300 watt
cost per unit=2 rupees 
therefore,$\dfrac {3300\times2\times15\times30}{60\times1000}$=49.5 rupees.

Multiple choice physics effects of electric current joule's law of heating thermal effect of electric current heating effect of electric current

What is the Joule's law ?

  1. $H=VRt$

  2. $H=I^2R^2t$

  3. $H=I^2Rt$

  4. $H=\dfrac{V^2}{R}t$
Reveal answer Fill a bubble to check yourself
C,D Correct answer
Explanation

Joules law can be stated as the quantity of heat generated (H) in a conductor of Resistance (R), when a current (I) flows through it for a time (t) is directly proportional to the square of the current, the resistance of the conductor, and the time for which the current flows.
So, $H=I^2Rt$
Now, for a conductor following Ohm's Law, $V=IR$, or, $I=\dfrac{V}{R}$
Therefore, $H=\dfrac{V^2}{R^2} \times R \times t=\dfrac{V^2}{R}t$

Multiple choice physics effects of electric current joule's law of heating thermal effect of electric current heating effect of electric current

The power dissipated as heat in a conductor of resistance $R$ due to current $I$ through it is called ________.

  1. Joule's loss

  2. $I^2R$ loss

  3. Either $(1)$ or $(2)$

  4. Neither $(1)$ nor $(2)$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The loss in power in electric circuit due to heat produced in conductors due to their resistance is called $Joule's \hspace{2mm} heat$.


Heat loss is given by $I^2R$.

Answer-(C)

Multiple choice physics effects of electric current joule's law of heating thermal effect of electric current heating effect of electric current

Laws of heating are given by

  1. Joule

  2. Ohm

  3. Maxwell

  4. Faraday
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Laws of heating are given by Joule 

Joule's Heating Effect:- When an electric current is passed through the conductor, it becomes hot and its temperature starts rising. This is known as the heating effect of current or Joule's heating effect.

Multiple choice physics effects of electric current joule's law of heating thermal effect of electric current heating effect of electric current

A given quantity of water boils in an electric kettle in $12 min$. The length of the heating element in the kettle is $\iota $. If the same quantity of water is to boil in $10 min$ on the same mains the length of an identical heating element is _______.

  1. $\iota $

  2. $\displaystyle \frac {\iota }{2}$

  3. $\displaystyle \frac {3\iota }{4}$

  4. $\displaystyle \frac {5\iota }{6}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Amount of heat required to boil a given quantity of water in a constant

$\displaystyle P=\frac {W}{t}$ or $W = H = P \times t = \displaystyle \frac {V^2}{R} \times t = \displaystyle \frac {V^2t _1}{R _1} = \displaystyle \frac {V^2t _2}{R _2}$

$\displaystyle \Rightarrow \frac {t _2}{t _1} = \frac {R _2}{R _1} = \frac {l _2}{l _1}$

or $\displaystyle \frac {10}{12} = \frac {l _2}{l _1} \Rightarrow l _2 = \frac {10}{12} \times l _1$

$\displaystyle l _2 = \frac {5}{6}l$