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 heater is connected to the 230 V mains supply. A current of 8 A flows through the heater.
(a) How much charge flows around the circuit each second?
What is nichrome? State its one use.
A heating coil has a resistance of 200 Ω. At what rate will heat be produced in it when a current of 2.5 A flows through it?
How much heat will an instrument of 12 W produce in one minute if it is connected to the heat produced by it?
An electric iron of 1100 W is operated for 2 hrs daily. What will be the electrical consumption expenses for that in the month of April? (The electric company charges Rs 5 per unit of energy).
Name any six domestic appliances based on the heating effect of electric current.
Rewrite the following statement by selecting the correct option:
1 A = ____________ mA.
In an electric bulb, coil of _______ metal is used.
The electricity bill specifies the usage in _______.
Explain the application of heating effect of electric current in an electric bulb with a diagram.
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?
B1, B2 and B3 are three identical bulbs connected as shown in Figure. When all the three bulbs glow, a current of 3A is recorded by the ammeter A.
- What happens to the glow of the other two bulbs when the bulb B1 gets fused?
- What happens to the reading of A1, A2, A3 and A when the bulb B2 gets fused?
- How much power is dissipated in the circuit when all the three bulbs glow together?
An electric cell produces electricity from the ______ ______ in it.
Name two electric devices for each where
- heating effect of current is used and
- magnetic effect of current is used.
______ wire is used in the filament of the bulbs.
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?
Write an expression for the amount of heat produced in a resistor when an electric current is passed through it stating the meanings of the symbols used.
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?
