An electric iron a power of 1100 W when set to higher temperature .If set to lower temperature,it uses 330 W power Find out the electric current and the respective resistance of 220 V.

An electrical iron uses a power of 1100 W when set to higher temperature. If set to lower temperature, it uses 330 W power. Find out the electric current and the respective resistances for the two settings.The iron is connected to a potential difference of 220 V.

An electrical iron uses a power of 1100 W when set to higher temperature. If set to lower temperature, it uses 330 W power. Find out the electric current and the respective resistances for the two settings. The iron is connected to a potential difference of 220 V.

An electric lamp is rated 40 W, 100 V. Find the current in the lamp and the resistance of the lamp.

If the bulb of 60 W is connected across a source of 220 V.find the electric current drawn by it .

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, find the power consumed by the bulb.

A 100 watt filament loses all its power by radiation when it is heated to a temperature of 2500 K. If the diameter of the filament is 0.2 mm and the surface emissivity of the filament is 0.5, find the length of the filament. (Stefan's constant sigma = 5.67 xx10^-8 W/m^2k^4 )

In a refrigerator one removes heat from a lower temperature and deposites to the surroundings at a higher temperature. In the process, mechanical work has to be done , which is provided by an electric motor. If the motor is of 1kW power , and heat is transferred from -3 ^@C to 27^@C , find the heat taken out of the refrigerator per second assuming its efficiency is 50% of a perfect engine.

Read the following paragraph and answer the questions given below it: The resistance of a metal falls when cooled below room temperature. Many scientists believed that the value of the resistance would become constant at some very low temperature, allowing the current to flow with little or no resistance. H. K. Onnes successfully liquefied helium in 1908 by cooling it to about 4 K. In 1911, while investigating the electrical property of very pure mercury. Onnes discovered that at a temperature of 4.2 kelvin, its resistance practically vanished. This new state, on account of its extraordinary property, is now called the superconducting state and the phenomenon is called superconductivity. A superconductor, below a certain critical temperature, offers almost zero resistance to a flow of current through it. Onnes also discovered that a superconductor exhibits persistent current: once set up, the current continues to flow for a very long time without an electric potential difference driving it and without significant loss. Superconductivity is used in many diverse areas, such as magnetically levitated trains, transmission of electricity, increasing speed of computers, in MRI (magnetic resonance imaging). At what temperature does the resistance of very pure mercury become almost zero?

Read the following paragraph and answer the questions given below it: The resistance of a metal falls when cooled below room temperature. Many scientists believed that the value of the resistance would become constant at some very low temperature, allowing the current to flow with little or no resistance. H. K. Onnes successfully liquefied helium in 1908 by cooling it to about 4 K. In 1911, while investigating the electrical property of very pure mercury. Onnes discovered that at a temperature of 4.2 kelvin, its resistance practically vanished. This new state, on account of its extraordinary property, is now called the superconducting state and the phenomenon is called superconductivity. A superconductor, below a certain critical temperature, offers almost zero resistance to a flow of current through it. Onnes also discovered that a superconductor exhibits persistent current: once set up, the current continues to flow for a very long time without an electric potential difference driving it and without significant loss. Superconductivity is used in many diverse areas, such as magnetically levitated trains, transmission of electricity, increasing speed of computers, in MRI (magnetic resonance imaging). Name the scientist who discovered superconductivity.