Advertisements
Advertisements
Question
The current passing through a room heater has been halved. What will happen to the heat produced by it?
Advertisements
Solution
The heat produced by the room heater will become one-fourth the previous quantity when the current passing through it is halved because the heat produced is directly proportional to the square of the current.
APPEARS IN
RELATED QUESTIONS
The safety device based on the heating effect of electric current is called a ______.
An electric room heater draws a current of 2.4 A from the 120 V supply line. What current will this room heater draw when connected to 240 V supply line?
How does the resistance of a wire vary with its:
diameter?
Why does the connecting cord of an electric heater not glow hot while the heating element does?
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
Explain why, tungsten is used for making the filaments of electric bulbs.
If the current flowing through a fixed resistor is halved, the heat produced in it will become:
Identify the figure and give its use.

Name any six domestic appliances based on the heating effect of electric current.
Write the mathematical expression for Joule’s law of heating.
These days when current in the circuit suddenly increases _______ switches are used.
Heating effect of current is called ______
Which of the following gases are filled in electric bulbs?
(a) Observe the diagram given below and state whether the bulb will glow or not when we switch on K.

(b) Is it safe to handle the bulb when the switch is OFF?
(c) Give a reason for your answer in (b).
A trip switch is a ______ safety device.
Define the following:
Electrolyte
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?
Tara, after completing her exams, went to her grandmother's house along with her younger brother Rahul. One day, Rahul came home after playing and switched on the fan and air conditioner. At the same time, his grandmother was preparing a milkshake for him using a mixer. Suddenly, they heard a big sound and the electricity of the house got shut down. Tara is called an electrician. He said the main reason for supply to shut down was overloading.
- What is overloading?
- Is overloading and short the same? When does short-circuiting take place?
- How can the effects of overloading be avoided?
State the law that explains the heating effect of current with respect to the measurable properties in an electrical circuit.
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?
