LED LIGHTS

How much power is consumed by a high power LED

• 100mW

• 150mW

• 250mW

• 350mW

Which lamp changes its colour due to age and ambient temperature

• LED Bulb

• Fluorescent lamp

• Incandescent lamp

• Sodium vapour lamp

Which function is performed by the

transistor in the LED light circuit?

• Mixer

• Driver

• Inverter

• Chopper

Which circuit is used to supply rated low

voltage DC and protect the LED light from

fluctuations?

• Rectifier circuit

• Regulator circuit

• Driver circuit

• Over load protection circuit

What is the name of the diode used in

emergency light to prevent the reverse flow of

battery charge?

• Tunnel diode

• Zener diode

• Varactor indicator

• Free wheeling diode

Which colour is produced by the

semiconductor material Aluminium Gallium

Phosphide (AlGaP) in LED?

• Red

• Blue

• Green

• Yellow

What is the value of series resistor (Rs)

connected to limit the load current to 10mA?

• 120 Ω

• 130 Ω

• 140 Ω

• 150 Ω

What is the condition for glowing LED?

• Forward biased

• Reverse biased

• Zener breakdown

• Avalanche breakdown

What is the function of the non-polar

capacitor in the LED circuit?

• Stops RF interference

• Smoothens DC supply

• Couples DC supply

• Couples AC supply

How to improve the lifespan of high power

LEDs?

• Reduce the conduction time

• Remove excess heat from light

• Dissipate some amount of energy

• Increase the size and shape of light