Collection of verified questions for Vidyut Dhara under General Science. Includes previous year exam questions with official answer keys and step-by-step solutions.
If the electric current flowing in a wire and the potential difference are both doubled, the electric power will:
The device that converts alternating current (AC) into direct current (DC) is called:
Transformers are used for:
How is white light produced in a fluorescent discharge tube?
A choke is attached to a fluorescent tubelight. The choke coil:
Assertion (A): Lightning conductors protect buildings from destruction. Reason (R): They divert and conduct the electrical charge safely to the ground. Code:
The characteristic of the wire used in a fuse is:
The filament of a halogen lamp is an alloy of:
What is the difference between CFL and LED lamps? 1. To produce light, CFL uses mercury vapor and phosphor, while LED lamp uses semiconductor material. 2. The average lifespan of CFL is much longer than that of LED lamp. 3. CFL is less energy-efficient compared to an LED lamp. Which of the statements given above is/are correct?
Organic Light Emitting Diodes (OLEDs) are used to create digital displays in many devices. What are the advantages of OLED displays over Liquid Crystal Displays (LCDs)? 1. OLED displays can be fabricated on flexible plastic substrates. 2. Roll-up displays embedded in clothing can be made using OLEDs. 3. Transparent displays are possible using OLEDs. Select the correct answer using the code given below:
Which gas is filled in a fluorescent tube?
Assertion (A): Light Emitting Diode (LED) lamps offer a longer lifespan compared to Compact Fluorescent Lamps (CFL). Reason (R): Light Emitting Diode (LED) lamps are more energy efficient than CFLs. Code:
With reference to street lighting, how do sodium lamps differ from LED lamps? 1. Sodium lamps produce light in 360 degrees, but it is not so in the case of LED lamps. 2. As street lights, sodium lamps have a longer lifespan than LED lamps. 3. The spectrum of visible light from sodium lamps is almost monochromatic, while LED lamps offer significant color advantages in street lighting. Select the correct answer using the code given below:
Grounding (earthing) is used in electrical appliances for:
In a three-pin electric plug, the longest pin should be connected to:
Which gas is inside an electric bulb?
Assertion (A): The temperature of a metal wire increases when electric current flows through it. Reason (R): Heat energy is released due to collisions between metal molecules. Code:
Of two bulbs in a house, one glows brighter than the other. Which of the two has higher electrical resistance?
Turbines and dynamos convert which energy into electrical energy?
In an electric motor:
When electrical energy is converted into motion:
A device which converts chemical energy into electrical energy is called:
A 100-watt bulb is kept switched on for 4 hours. The units of electrical energy consumed will be:
A device based on electromagnetic induction is:
The device that converts electrical energy into mechanical energy is: