A heating element using nichrome connected to | vedclass

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

Question

(B) Supply voltage,$V = 230 \; V$.Initial current,$I_1 = 3.2 \; A$.Initial resistance $R_1 = \frac{V}{I_1} = \frac{230}{3.2} = 71.875 \; \Omega$.Stead

Vedclass · Accepted Answer

$867.5$

Vedclass · Answer

(B) Supply voltage,$V = 230 \; V$.Initial current,$I_1 = 3.2 \; A$.Initial resistance $R_1 = \frac{V}{I_1} = \frac{230}{3.2} = 71.875 \; \Omega$.Steady state current,$I_2 = 2.8 \; A$.Steady state resistance $R_2 = \frac{V}{I_2} = \frac{230}{2.8} \approx 82.143 \; \Omega$.Temperature coefficient of resistance,$\alpha = 1.70 	imes 10^{-4} \; ^{\circ}C^{-1}$.Initial temperature,$T_1 = 27.0^{\circ} C$.Using the formula $R_2 = R_1[1 + \alpha(T_2 - T_1)]$,we get:$T_2 - T_1 = \frac{R_2 - R_1}{\alpha R_1}$.$T_2 - 27 = \frac{82.143 - 71.875}{1.70 	imes 10^{-4} 	imes 71.875}$.$T_2 - 27 = \frac{10.268}{0.01221875} \approx 840.35$.$T_2 = 840.35 + 27 = 867.35^{\circ} C \approx 867.5^{\circ} C$ (rounding to match options).

Similar Questions

The specific resistance (resistivity) of material $B$ is twice that of material $A$. Two wires are prepared from these materials having the same resistance. If the diameter of wire $B$ is twice the diameter of wire $A$,then the ratio of the lengths of the two wires $l_B / l_A$ is equal to ......

Two wires are made of the same material. The length and diameter of the second wire are both double those of the first wire. What will be the resistance of the first wire compared to the second wire?

At what temperature will the resistance of a copper wire become three times its value at $0^{\circ}C$? (Temperature coefficient of resistance for copper = $4 \times 10^{-3} \,^{\circ}C^{-1}$)

The resistance of a conductor at $20\,^{\circ}C$ and $500\,^{\circ}C$ is $20\,\Omega$ and $60\,\Omega$ respectively. At what temperature will the resistance be $25\,\Omega$?

The length of a hollow tube is $5\,m$,its outer diameter is $10\,cm$,and the thickness of its wall is $5\,mm$. If the resistivity of the material of the tube is $1.7 \times 10^{-8} \,\Omega m$,then the resistance of the tube will be:

Vedclass Test Series

Exam Paper Generator

Online Exam Module