Study HubHubPage 115/118Scan verified MCQs with the answer highlighted, then open explanations when you want the reasoning.
Read Mode
Electronic Components
In electronic devices, vacuum tubes are replaced by?
Vacuum tubes in electronic devices were replaced by transistors because transistors are smaller, more reliable, consume less power, and generate less heat compared to vacuum tubes.
Read Mode
Semiconductor Devices
Which one of the following is a semiconductor device that is used to increase the power of incoming signals by preserving the shape of the original signal?
A transistor is a semiconductor device used to amplify signals while preserving the original signal's shape. It increases the power of incoming signals, making it fundamental in electronic circuits. The other options are either incorrect or less specific for this function.
Read Mode
Sound And Audio Devices
What is the primary function of a microphone?
A microphone's primary function is to convert sound waves into electrical signals or digital data, enabling sound to be recorded, transmitted, or processed. Options A, C, and D describe functions unrelated to microphones.
Read Mode
Acronyms
What does LASER stand for? A) Light alteration stimulated emission of radiation B) Light amplification by stimulated emission of radiation C) Light absorption stimulated emission of radiation D) None of these
LASER stands for 'Light Amplification by Stimulated Emission of Radiation,' which accurately describes the physical process behind laser operation.
Read Mode
Semiconductor Devices
What is the full form of LED?
LED stands for Light Emitting Diode, which is a semiconductor device that emits light when an electric current passes through it. This is the widely accepted and correct full form of LED.
Read Mode
Abdul Qadeer Khan education
Dr. Abdul Qadeer Khan obtained his physics degree from ___?
Dr. Abdul Qadeer Khan obtained his degree in physics from the Catholic University of Leuven in Belgium, not Karachi. Therefore, option B is correct.
Read Mode
Seismic waves
Earthquake waves increase in velocity upon entering the mantle.
Seismic waves generally increase in velocity when they enter the Earth's mantle due to the higher density and rigidity of mantle materials compared to the crust. This causes the waves to travel faster through the mantle.
Read Mode
Nobel Prize (women scientists)
Which of the following women scientists won the Nobel Prize twice?
Marie Curie is the only woman scientist who has won the Nobel Prize twice, once in Physics (1903) and once in Chemistry (1911).
Read Mode
History of Chemistry
Which Muslim scientist is considered to be the founder of chemistry?
Jabir bin Hayan is widely regarded as the father of chemistry due to his pioneering work in alchemy and chemical processes, laying the foundation for modern chemistry. The other options are notable scholars but not credited with founding chemistry.
Read Mode
Electricity (Conductors/Insulators)
Substances which allow current to pass through are:
Conductors are substances that allow electric current to pass through them easily due to the presence of free electrons. Inductors are components that store energy in a magnetic field, insulators prevent current flow, and wires are physical conductors but the best general term is 'Conductors'.