Current flowing through a conductor produces heat. This heat depends on quantity of current flowing through the conductor, time and resistance of the conductor. We can write: H α I²H α RH α tBy combining these three relation, we get:H α I²Rt H = K. I²Rt, where K is a constant.K= (H/(I²Rt))K= H for I=1 … Read more
Three sums of electrical power have been discussed in this video. This is the second part of sum discussion . Sum 1: A water heater has a rating of 4 KVA , 240 V.a) What is the electrical energy consumed by it in:i)KWhr andii) in Joul.if it is used for 180 minutes.b) Find the cost … Read more
Three sums of electrical power have been discussed. Here. This sum will give a basic idea of finding electrical power and electrical energy consumed by a load or electrical energy supplied by a source like a battery. The sums are: Two resisters of value 6 ohm and 12 ohms are connected in series across … Read more
Rating of Electrical Appliance:These are normal rating of electrical appliances available in the market. Electric bulb-100W, 60W, 15W Fluorescent tube- 40W, 20 W, 80W CFL lamp- 5W, 15W, 20 W, 40W, 90W Refrigirator- 220 W Micro Oven- 3000 W Electric Iron- 700WInduction Heater – 1500 W From the rating of the electrical appliance , … Read more
Th S.I. unit of energy is joul(J). Let the power (p) of an electrical appliance = P wattLet it is used for t seconds. Then Electrical energy consumed (W) = P x t watt-secondi.e. W = Pt Watt-secondor W = Pt Joul (Joul is Mechanical unit equivalent of Watt-second) In practice bigger unit like Watt-Hour … Read more
Electrical Power: Rate of electrical energy supplied by a source e.g. a power station or an alternator or a dc battery etc is called electrical power. ∴ Power = Electrical Energy supplied / Time if Power = PEnergy supplied = Wand Time = T Then P = W / Tif W is in JoulT in … Read more
Ohm’s Law: It can be defined as “The potential difference (P.D.) across a conductor is proportional to the current flowing through it provided that physical conditions remain constant.” If V = Potential Difference (P.D.)I= current Then we can write V ∝ I Or V= I. R R= Constant and it is known as resistance of … Read more
Suppose a Current I flows through a circuit as shown in the figure. The voltage across the resistance is V . The P.D. is the work done to move a charge Q from one point to another point, between which the p.d. is applied. W = QVBut, Q= I.t ∴ W = VIt Another energy … Read more
Emf: Emf is defined as work done per unit charge in taking a positive charge through the complete circuit ( the circuit outside the source (cell) and inside of the source. emf is represented by greek letter ε If W is the work done when a test charge of q0 is taken through the complete … Read more
Resistance: Resistance of a conductor is the opposition offered by the conductor to the flow of current through it. Resistances are of two type fixed resistance and variable resistance. Reason of resistance: The resistance is due to collision of moving electrons while moving from negative terminal to positive terminal. In this process when electrons collide … Read more