मराठी

An Electric Heater of Resistance 8 ω Takes a Current of 15 a from the Mains Supply Line. Calculate the Rate at Which Heat is Developed in the Heater.

Advertisements
Advertisements

प्रश्न

An electric heater of resistance 8 Ω takes a current of 15 A from the mains supply line. Calculate the rate at which heat is developed in the heater. 

 

Advertisements

उत्तर

I = 15 A, R = 8 Ω
Rate of heat produced = Power = I2R = (15)2(8) = 1800 J/s

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 4: Electricity - Exercise 8

APPEARS IN

लखमीर सिंह Physics [English] Class 10
पाठ 4 Electricity
Exercise 8 | Q 18

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

1 calorie =  _________ joule.


What is the meaning of the symbol kWh? Which quantity does it represent?


Calculate the cost of operating a heater of 500 W for 20 hours at the rate of Rs 3.90 per unit.


An electric heater is rated at 2 kW. Electrical energy costs Rs 4 per kWh. What is the cost of using the heater for 3 hours?

(a) Rs 12
(b) Rs 24
(c) Rs 36
(d) Rs 48


State whether an electric heater will consume more electrical energy or less electrical energy per second when the length of its heating element is reduced. Give reasons for your answer.


The table below shows the current in three different electrical appliances when connected to the 240 V mains supply: 

Appliance Current
Kettle 8.5 A
Lamp 0.4 A
toaster 4.8 A
  1. Which appliance has the greatest electrical resistance? How does the data show this?
  2. The lamp is connected to the main supply by using a thin, twin-cored cable consisting of live and natural wires. State two reasons why this cable should not be used for connecting the kettle to the mains supply.
  3. Calculate the power rating of the kettle when it is operated from the 240 V mains supply.
  4. A main takes the kettle abroad where the mains supply is 120 V. What is the current is the kettle when it is operated from the 120 V supply?

Why is an electric light bulb not filled with air? Explain why argon or nitrogen is filled in an electric bulb.


A current of 0.2 A flows through a wire whose ends are at a potential difference of 15 V.
calculate:
(i) the resistance of the wire and
(ii) the heat energy produced in 1 minute.


An immersion heater rated 1000 W, 220 V is used to heat 0.01 m3 of water. Assuming that the power is supplied at 220 V and 60% of the power supplied is used to heat the water, how long will it take to increase the temperature of the water from 15°C to 40°C?


A radio set of 60 W runs for 50 hours. How much electrical energy is consumed? Give your answer in kWh.

Name three main characteristics of an heating element.


The electric bulbs used these days have a coil-coiled filament. State its reason.


State two advantages of filling an inert gas in an evacuated electric filament lamp.


Name a metal that is used as an electron emitter. Give one reason for using this metal.


What would happen and why, to an electric bulb when it is connected across a supply of voltage (i) lower (ii) higher than its proper rating?


What is the order of current drawn by appliances connected to the ‘power circuit’ of a household?


How is the amount of heat produced calculated due to the passage of current in a metallic conductor? Derive an expression for it.


An electric bulb is rated as 100W – 250V. What information does it convey? Calculate the current through the filament of the bulb.


Electric power is inversely proportional to ____________.


In the given figure, the emf of the cell is 2.2 V, and if internal resistance is 0.6 Ω. Calculate the power dissipated in the whole circuit.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×