Advertisements
Advertisements
Question
Calculate the quantity of heat that will be produced in a coil of resistance 75 Ω if a current of 2A is passed through it for 2 minutes.
Advertisements
Solution
R = 75 Ω, i = 2A, t = 2 minutes = 2 × 60 s = 120 s
Heat energy produced in the coil, H = i2Rt
= 22 × 75 × 120
= 300 × 120 = 36000 J
RELATED QUESTIONS
If two resistors of 25 Ω and 15 Ω are joined together in series and then placed in parallel with a 40 Ω resistor, the effective resistance of the combination is :
(a) 0.1 Ω
(b) 10 Ω
(c) 20 Ω
(d)40 Ω
Draw a V-I graph for a conductor at two different temperatures. What conclusion do you draw from your graph for the variation of resistance of conductor with temperature?
State the order of resistivity of (i) a metal, (ii) a semiconductor and (iii) an insulator.
Name a substance of which the resistance remains almost unchanged by the increase in temperature.
Bends in a rubber pipe reduce the flow of water through it. How would the bands in a wire affect its electric resistance?
Name the material of wire used for making standard resistances. Give a reason.
State a relation between electrical power, resistance and potential difference in an electrical circuit.
What is a resistance? Define it with respect to Ohm’s law,
Three resistors of 6Ω, 3Ω and 2Ω are connected together so that their total resistance is greater than 6Ω but less than 8Ω Draw a diagram to show this arrangement and calculate its total resistance.
When a 4 Ω resistor is connected across the terminals of a 2 V battery, the number of coulombs passing through the resistor per second is:
