Types of Lamps
Trending Questions
A 100-watt electric bulb is operated for 10 hours. How many units of electrical energy have been consumed?
A bulb is rated at 200V-100W. What is it's resistance? Five such bulbs burn for 4 hours. What is the electrical energy consumed? Calculate the cost if the rate is 4.60 ruppes per unit.
State the colours of live, neutral and earth wires in a cable according to international convention.
Why is electricity considered the most convenient form of energy?
Why the filament of bulb has high melting point?
Explain:
(b) Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
Among the following which one is used in detecting fake notes and documents?
UV rays from fluorescent lamps
Gamma rays from fluorescent lamps
Infrared rays from fluorescent lamps
Microwaves from fluorescent lamps
In a discharge lamp, if colour of the light is green, then which gas does the lamp contains?
Nitrogen gas
Neon gas
Chlorine gas
Hydrogen gas
Among all types of light bulbs, the most energy efficient is
Filament lamp
Arc lamps
LED lamps
Discharge lamps
In a cathode ray tube, the cathode plate is coated with oxide of barium or strontium because
They increase the work function of the plate
They increase the melting point of the plate
They decrease the melting point of the plate
They decrease the work function of the plate
The filament used in the bulb is of high resistance.
True
False
What is the difference between incandescent and LED bulbs?
Why is Tungsten metal selected for making the filaments of incandescent lamp/bulbs?
Does phosphorus glow under black light?
The importance of glass enclosure in incandescent bulb is
to preserve and protect the filament from cooling.
to preserve the temperature around the filament.
to preserve and protect the filament from evaporating.
to preserve and protect the filament from extra heating.
Why is UV light used in the photoelectric effect?
On which principle does discharge lamp work?
Vaporization of gases by the application of electric field.
Ionization of gases by the application of magnetic field.
Ionization of gases by the application of electric field.
Ionization of gases by the application of heat externally.
Name the liquid metal that CFL bulbs contain which is detrimental to environment.
Sodium
Bromine
Mercury
Helium
Name the most convenient and widely used form of energy.
What happens to the power of a bulb if it's broken filament is rejoined and lighted?
The brigthtness will be lesser, usually for a short time, until the filament fails.
The brigthtness will be more, usually for a longer time period, until the filament fails.
More power is consumed in very less time.
More power is consumed in longer time.
According to the new convention, the colour of live wire is.
light blue
yellow
green
brown
The colour of light depends on the gas inside the discharge lamp.
True
False
State the colors of live, neutral and earth wires in a cable according to international convention.
Working of safety fuse
What is 1 watt-hour?
Which gas is filled in a bulb to prevent oxidation of tungsten wire?
Oxygen
Carbon dioxide
Nitrogen
Helium
Heating coil in fluorescent lamps are coated with thorium oxide to
reflect the electrons
absorb the electrons
decrease electron emission efficiency
increase electron emission efficiency
Mention the reason why tungsten is a suitable metal for Thermionic emission
Which of the statement/s is/are true for a fluorescent lamp?
A phosphour coating on the inside part of the lamp to glow by excitation of mercury vapour.
A fluorescent lamp converts heat energy into useful light.
A fluorescent lamp converts electrical energy into useful light
An electric current in the gas excites hydrogen vapour, which produces medium-wave ultraviolet light.
