Tag: science & technology

Quizzes (551) Questions (11015)

Questions Related to science & technology

Multiple choice general knowledge science & technology

chgrp command is for

  1. Change Gear

  2. Change Guard

  3. Change Graphics

  4. Change Group
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The 'chgrp' command in Unix/Linux is specifically used to change the group ownership of a file or directory. It stands for 'change group' and is used to modify which group has access rights to a file. This is different from 'chown' which changes both user and group ownership. Group ownership is a key component of Unix's multi-user security model.

Multiple choice general knowledge science & technology

Xen is known for?

  1. Office Suite

  2. Multimedia

  3. Virtualization

  4. Xchange Express Network
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Xen is a well-known open-source virtualization software that runs directly on hardware (type-1 hypervisor). It allows multiple operating systems to run simultaneously on a single computer by creating and managing virtual machines. Xen was developed at Cambridge University and is widely used in cloud computing infrastructure, including by Amazon Web Services.

Multiple choice general knowledge science & technology

Devices are represented as

  1. devices

  2. directories

  3. files

  4. ports
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In Unix-like systems, devices are represented as files in the /dev directory. This allows uniform access to hardware using standard file operations. Directories organize the filesystem, ports are communication endpoints, and 'devices' is circular.

Multiple choice general knowledge science & technology

What is considered a normal blood pressure?

  1. Systolic blood pressure less than 90 and diastolic blood pressure less than 150

  2. Systolic blood pressure less than 140 and diastolic blood pressure less than 90

  3. Systolic blood pressure less than 180 and diastolic blood pressure less than 150

  4. dummy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Normal blood pressure is typically defined as systolic less than 120 mmHg and diastolic less than 80 mmHg. However, guidelines vary - some sources use 140/90 as the threshold for hypertension. Option B (systolic <140, diastolic <90) aligns with older, less stringent standards and is the best available answer.

Multiple choice general knowledge science & technology

What kind of medication used to treat hypertension works by excreting extra water and salt to lower blood pressure?

  1. ACE inhibitors

  2. Anti-adrenergic drugs

  3. Diuretics

  4. Antibiotics
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Diuretics (often called 'water pills') work by increasing urine production, helping kidneys eliminate excess sodium and water from the body, which reduces blood volume and lowers blood pressure. ACE inhibitors and anti-adrenergic drugs work through different mechanisms.

Multiple choice general knowledge science & technology

What's the relationship between coronary artery disease (CAD) and cholesterol?

  1. An elevated level of low density lipoprotein (LDL) and a decreased level of high density lipoprotein (HDL) are associated with a reduced risk of coronary artery disease.

  2. A decreased level of LDL and an elevated level of HDL are associated with a reduced risk of coronary artery disease.

  3. Levels of LDL and HDL should be about the same to reduce the risk of coronary artery disease.

  4. dummy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

LDL (low-density lipoprotein) is considered 'bad' cholesterol because it contributes to plaque buildup in arteries, while HDL (high-density lipoprotein) is 'good' cholesterol that helps remove cholesterol from arteries. Therefore, lower LDL levels and higher HDL levels are associated with reduced cardiovascular risk. Option A incorrectly states the opposite relationship, and option C incorrectly suggests equal levels are optimal.

Multiple choice general knowledge science & technology

What is the long form of "MASER"?

  1. Microwave Amplification by Stimulated Emission of Radiation

  2. Macrowave Amplification by Stimulated Emission of Radiation

  3. Microwave Amplification by Stimulated Emitter for Radiation

  4. Microwave Amplification by Stimulated Emission of Radiator
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

MASER stands for Microwave Amplification by Stimulated Emission of Radiation. It's the microwave-frequency analog of a laser. Option B incorrectly uses 'Macrowave,' while options C and D have incorrect word choices ('Emitter' vs 'Emission,' 'Radiator' vs 'Radiation').

Multiple choice general knowledge science & technology

In 2006, a study reported that mice that were bred to develop atherosclerosis experienced a decrease in artery plaque buildup when they were fed vegetables. By what percentage did the artery plaque buildup decrease?

  1. 32 percent

  2. 34 percent

  3. 36 percent

  4. 38 percent
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This question refers to a specific 2006 research study on atherosclerosis in mice. Without access to the original study data, the exact percentage (38% claimed) cannot be independently verified. The question requires recall of a specific research finding.