A coil develops heat of 800 , cal/sec when 20 | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) The rate of heat production is given by $P = \frac{H}{t} = 800 \, cal/sec$. Converting this to $SI$ units (Joules per second or Watts): $P = 800 \

Vedclass · Accepted Answer

$0.12$

Vedclass · Answer

(C) The rate of heat production is given by $P = \frac{H}{t} = 800 \, cal/sec$. Converting this to $SI$ units (Joules per second or Watts): $P = 800 	imes 4.2 \, J/sec = 3360 \, W$. The formula for electrical power in terms of voltage $V$ and resistance $R$ is $P = \frac{V^2}{R}$. Substituting the given values: $3360 = \frac{20^2}{R}$. $3360 = \frac{400}{R}$. $R = \frac{400}{3360} = \frac{40}{336} \approx 0.119 \, \Omega$. Rounding to two decimal places,we get $R \approx 0.12 \, \Omega$.

$A$ coil develops heat of $800 \, cal/sec$ when $20 \, V$ is applied across its ends. The resistance of the coil is .............. $\Omega$ $(1 \, cal = 4.2 \, J)$.

Similar Questions

$A$ lamp is rated at $240 \ V, 60 \ W$. When in use,the resistance of the filament of the lamp is $20$ times that of the cold filament. The resistance of the lamp when not in use is: (in $\Omega$)

Assertion: Long distance power transmission is done at high voltage.
Reason: At high voltage supply,power losses are less.

$A$ rise of temperature of $4\,^oC$ is observed in a conductor by passing a current. If the current is tripled,the rise in temperature will be .............. $^oC$.

Which of the following is not equal to watt?

In an electric heater, $4\, A$ current passes for $1\, \text{minute}$ at a potential difference of $250\, V$. The power of the heater and the energy consumed will be, respectively:

Vedclass Test Series

Exam Paper Generator

Online Exam Module