Advertisements
Advertisements
Question
An electric kettle rated at 220 V, 2.2 kW, works for 3 hours. Find the energy consumed and the current drawn.
Advertisements
Solution
Given:
V = 220 V
P = 2.2 kW = 2.2 x 103 w
t = 3 h
Electrical energy, E = P x t
= 2.2 kW x 3 h
= 6.6 kWh
Current drawn, I = P/V
= `2.2x10^3/220`
= 10 A
APPEARS IN
RELATED QUESTIONS
Why does the cord of an electric heater not glow while the heating element does?
Write Joule's law of heating.
Why are the coils of electric irons and electric toasters made of an alloy rather than a pure metal?
An electric fuse works on the:
(a) chemical effect of current
(b) magnetic effect of current
(c) lighting effect of current
(d) heating effect of current
Two exactly similar heating resistances are connected (i) in series, and (ii) in parallel, in two different circuits, one by one. If the same current is passed through both the combinations, is more heat obtained per minute when they are connected in series or when they are connected in parallel? Give reason for your answer.
Give Scientific reasons.
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster etc, an alloy such as Nichrome is used, not pure metals.
Identify the figure and give its use.

Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
Name any six domestic appliances based on the heating effect of electric current.
The ‘live’ and the ‘neutral’ wires have potential difference of _______.
Name any two appliances which works on the phenomenon of heating effect of electric current.
An electric iron consumes energy at the rate of 420 W when heating is at the maximum rate and 180 W when heating is at the minimum rate. The applied voltage is 220 V. What is the current in each case?
What is an electric fuse made up of?
What are the factors affecting heating effect of electric current?
Assertion: A current-carrying wire should be charged.
Reason: The current in a wire is due to the flow of free electrons in a definite direction.
An electrochemical cell converts ______ energy into ______ energy.
If 220 V potential difference is applied across an electric bulb, a current of 0.45 A flows in the bulb. What must be the power of the bulb?
Two students decided to investigate the effect of water and air on iron object under identical experimental conditions. They measured the mass of each object before placing it partially immersed in 10 ml of water. After a few days, the object were removed, dried and their masses were measured. The table shows their results.
| Student | Object | Mass of Object before Rusting in g |
Mass of the coated object in g |
| A | Nail | 3.0 | 3.15 |
| B | Thin plate | 6.0 | 6.33 |
What might be the reason for the varied observations of the two students?
The graph of voltage vs current for four different materials is shown below.

Which of these four materials would be used for making filament of bulb?
