V = IR …[Where R is proportionality constant called resistance of conductor] In parallel combination, the potential difference across each resistor is the same and is equal to the total potential difference. A2 = ( (2))/ Will the potential difference across the 2 Ω resistor be the same as that across the parallel combination of 4 Ω resistors Procedure: A three core, cord having three wires coated with insulation of red, brown and green colour, is used for connecting die appliance to the mains for drawing current from the mains. I = 1 A (Board of Trade) unit and is used throughout the world in calculating the amount of electric energy consumed. ∴  Energy consumed in hour = 100 × 60 × 60J = 360000 J. This means R will decrease with an increase in the area of conductor and vice versa. But what exactly is electricity? They are generally used in staircases, long corridors etc. Answer: The leads are much thicker than the filament wire. 1 Watt power is consumed when 1 Ampere of current flows through a device at a potential difference of 1 Volt. CBSE Class 10 Science Notes Chapter 12 Electricity Pdf free download is part of Class 10 Science Notes for Quick Revision. Minimum resistance is / Ω unit of electric potential difference is volt and denoted by ‘V’ This is named in honour of Italian Physicist Alessandro Volta. l = 3L Answer: We know, Current = Voltage/Resistance For a given bulb, the filament would have a definite characteristic resistance. Class 10 Physics Electricity: Electric Power: Electric Power. If one coulomb of charge passes between these points: the amount of energy supplied by the charge would be V joule. unit of resistivity (ρ) is Ωm. Now, Question 12: Why is heating coil wound in the form of a helix in electric stove? V = 4 V Question 2: Define Watt hour. V = I R H = I2Rt ……(iv) P = \(\frac { W }{ T }\) 1 C = 1/(1.6 × 〖10〗^(−19) ) electrons Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are as essential for the working of basic functionalities of the website. Which of these systems mentioned by you is better and why? Answer: It is because, the temperature of heating element is around 1000°C, whereas visible light is produced if the temperature rises above 1500°C. NCERT Solutions for Class 9 Maths Chapter 12 Heron's Formula In Hindi. Question 16: State two advantages of ‘the ring system of house wiring’. Since the material is same, ρ is same in all the three cases. Answer: When an electric current passes through a metallic wire, the wire becomes hot and the whole of electric energy is converted into heat energy. Thus the person touching it does not get any shock. 1C = 1A × 1s Question 8: What is electric power? Some examples are as follows : When electric energy is supplied to an electric bulb, the filament gets heated because of which, it gives light. Thus the resistance of the leads is much smaller than that of filament wire. I = \(\frac { 1000W }{ 220V }\) = 4.5 A of about 200°C and is usually made from an alloy of 50% tin and 50% lead. unit of electric power is Watt. Electric power is a widely used term in physics as you must be aware of. The reason is that in the case of over-loading, if fuse wire is connected in neutral wire, it will certainly melt and break, but the electric appliance still be in contact with the live wire, so if any person happens to touch the appliance, he will get a shock which may prove fatal. in series combination equivalent 1/ = 2/8 Extra Question In an electrical circuit two resistors of 2 Ω and 4 Ω respectively are connected in series to a 6 V battery. Give one reason for using this metal. Then the power flowing out of the main switch is distributed in house by the common ring or three wire system. Compare the resistance and the resistivity of the three conductors.