Advertisements
Advertisements
Question
Explain why, filament type electric bulbs are not power efficient.
Advertisements
Solution
Filament type of electric bulbs are not power efficient because a lot of power gets wasted as heat.
APPEARS IN
RELATED QUESTIONS
An electric lamp is labelled 12 V, 36 W. This indicates that it should be used with a 1 V supply. What other information does the label provide?
Which uses more energy: a 250 W TV set in 1 hour or a 1200 W toaster in 10 minutes?
The diagram below shows a circuit containing a lamp L, a voltmeter and an ammeter,. The voltmeter reading 3 V and the ammeter reading is 0.5 A.
What is the resistance of the lamp?
What is the power of the lamp?
Name two gases which are filled in filament type electric light bulbs.
A current of 2 A is passed through a coil of resistance 75Ω for 2 minutes. (a) How much heat energy is produced? (b) How much charge is passed through the resistance?
A bulb marked 12 V, 24 W operated on a 12 volt battery for 20 minutes. Calculate:
(i) the current flowing through it, and
(ii) the energy consumed
A bulb with rating 250 V, 100 W is connected to a power supply of 220 V situated 10 m away using a copper wire of area of cross-section 5 mm2. How much power will be consumed by the connecting wires? Resistivity of copper = 1.7 × 10−8 Ωm
Two resistors A and B of 4 Ω and 6 Ω, respectively are connected in parallel. The combination is connected across a 6 volt battery of negligible resistance. Calculate the power dissipated in each resistor.
Why is heating element wound on a long porcelain rod in a room heater.
Why is a concave reflector placed behind the heating element in a room heater.
What changes in energy occur in an electric heater?
A device is used to transform 12 V a.c. to 200 V a.c. What is the name of this device? Name the principle on which it works.
How does the heat produced by die passage of current in a metallic wire depend on the current in the wire?
What is the resistance of an appliance rated at V volt, P watt?
Out of the three fuses with current ratings 5A, 10A, 15A, which one is to be connected in a geyser circuit marked 3 kW, 220V? Give reason for your answer.
A bulb is connected to a battery of e.m.f. 6V and internal resistance 2Ω A steady current of 0.5A flows through the bulb. Calculate the total energy supplied by the battery in 10 minutes.
A consumer uses 4 lamps of 60 watt, 2 lamps of 40 watt, and 2 lamps of 100 watt. All these are used for 6 hour daily. Find the total bill for 30 days when the rate of energy is 75 paise per unit and the meter rent is Rs. 1.
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.

