[" A "2kW" heater a "200W" TV and three "100W" lamps are all switched on from "6p.m" ,to "10p.m" .What is the "],[" total cost at Rs."5.50" per kWh? "],[" What is the maximum power in kilowatts of the appliance that can be connected safely to a "13A;230],[" mains socket? "]

A 2 kW heater, a 200 WTV and three 100W lamps are all switched on from 6 p.m. to 10 p.m. What is the total cost at Rs. 5.50 per kWh?

Radha's house is fitted with 2 lamps of 60W each and 2 fans consuming 0.4A each . If energy is upplied at 200V and coats Rs. 2.50 per kWh. Find the monthly bill if all the appliances run for 10 hours a day.

Radha's house is fitted with 2 lamps of 60W each and 2 fans consuming 0.4A each . If energy is upplied at 200V and coats Rs. 2.50 per kWh. Find the monthly bill if all the appliances run for 10 hours a day.

Radha's house is fitted with 2 lamps of 60W each and 2 fans consuming 0.4A each . If energy is upplied at 200V and coats Rs. 2.50 per kWh. Find the monthly bill if all the appliances run for 10 hours a day.

If a young man rides his motor cycle at 25 k . p . h , he has to spend Rs. 2 per km on petrol, if he rides it at ạ faster speed of 40k.p.h. , the petrol cost increases to Rs. 5 per k m . He has Rs. 100 to spend on petrol and wishes to find what is the maximum distance, he can travel within the hour. Express this as a linear programming problem and then solve it.

The main meter of a house contains a 5A fuse. 4 lamps rated 220V- 60 w run in the house . Under this condition , can a heater rated 220 V - 1000W be used ? What minimum number of lamps should be switched of to run the heater safely ?

A 10 m long nichrome wire having 80 Omega resistance has current carrying capacity of 5 A. This wire can be cut into equal parts and equal parts can be connected in series or parallel. What is the maximum power which can be obtain as heat by the wire from a 200 V mains supply? (in kW)

A 10 m long nichrome wire having 80 Omega resistance has current carrying capacity of 5 A. This wire can be cut into equal parts and equal parts can be connected in series or parallel. What is the maximum power which can be obtain as heat by the wire from a 200 V mains supply? (in kW)

(a) What is meant by "electric power"? Write the formula for electric power in terms of potential difference and current. (b) The diagram below shows a circuit containing a lamp L, a voltmeter and an ammeter. The voltmeter reading is 3V and the ammeter reading is 0.5A. (i) What is the resistance of the lamp? (ii) What is the power of the lamp? (c) Define kilowatt-hour. How many joules are there in one kilowatt-hour? (d) Calculate the cost of operating a heater of 500 W for 20 hours at the rate of Rs 3.90 per unit.

An 1800 W toaster, a 1.3 kW electric fan and a 100 W lamp are plugged in the same 120 V circuit i.e., all the three devices are in parallel. What is the approximate value of the total current (i.e. the sum of current drawn by the three devices) through the circuit ?