GK: Class 12 General Q&A · Page 87
3,658 free answers on GK (General) for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
What is the value of cos 72 degrees in fraction?
Cos 72° = (√5 - 1)/4 (exact form) This equals approximately 0.309. This value comes from the geometry of a regular pentagon and involves the golden ratio.
- GeneralClass 12All
How do you measure mass?
Mass is measured using: Balance scales - Compare against known standard masses Electronic scales - Display mass digitally Triple-beam balances - Used in laboratories for precision Spring scales - Actually measure weight but display mass values Place the object on the scale and read the measurement directly in the desired unit (grams, kilograms, etc.).
- GeneralClass 12All
How to calculate body mass in kg?
To determine your body mass in kilograms: Use a calibrated scale set to kilogram units Weigh yourself in the morning before eating, wearing minimal clothing Read the displayed value directly - this is your mass in kg If your scale shows pounds, divide by 2.205 to convert to kilograms (1 kg = 2.205 lbs).
- GeneralClass 12All
How to calculate mass in kg?
To calculate or convert mass to kilograms: From grams: Divide by 1,000 (e.g., 5,000 g = 5 kg) From milligrams: Divide by 1,000,000 From pounds: Multiply by 0.4536 (e.g., 150 lbs = 68 kg) From metric tons: Multiply by 1,000 Always ensure you're starting with a mass unit, not weight in Newtons.
- GeneralClass 12All
How to calculate mass in grams?
To calculate mass in grams: From kilograms: Multiply by 1,000 (e.g., 2.5 kg = 2,500 g) From milligrams: Divide by 1,000 From ounces: Multiply by 28.35 Direct measurement: Use a scale calibrated in grams Grams are ideal for measuring smaller objects, food portions, and laboratory samples
- GeneralClass 12All
How do I convert mass to kg?
. Conversion factors to kilograms: Grams to kg: Divide by 1,000 Milligrams to kg: Divide by 1,000,000 Pounds to kg: Multiply by 0.4536 Ounces to kg: Multiply by 0.0283 Stones to kg: Multiply by 6.35 Formula: kg = (original value) × (conversion factor)
- GeneralClass 12All
What is mass in physics?
Mass is a fundamental property of matter that measures the amount of substance in an object. Unlike weight, mass remains constant regardless of location and represents the object's resistance to acceleration (inertia). In physics, mass is measured in kilograms (kg) in the SI system and determines how much matter is contained within an object.
- GeneralClass 12All
What is the SI unit of mass?
The SI (International System of Units) unit of mass is the kilogram (kg). One kilogram is defined by the International Bureau of Weights and Measures and serves as the standard measurement for mass worldwide. Other common units include grams (g), milligrams (mg), and metric tons.
- GeneralClass 12All
What are 3 units for mass?
The three most commonly used units for mass are: Kilogram (kg) - The SI base unit, used for everyday measurements Gram (g) - One-thousandth of a kilogram, used for smaller objects Milligram (mg) - One-thousandth of a gram, used in medicine and chemistry Other units include metric tons (1,000 kg), pounds (lb), and ounces (oz) in imperial systems.
- GeneralClass 12All
What is the basic unit of mass?
The basic unit of mass in the metric system is the kilogram (kg). However, the gram (g) is often considered the fundamental unit in chemistry and everyday measurements, with the kilogram being 1,000 grams. All other mass units are derived from these base units.
- GeneralClass 12All
What is the smallest unit of mass?
In practical measurements, the smallest commonly used unit is the microgram (µg), which equals one-millionth of a gram. In atomic physics, much smaller units like atomic mass units (amu) or electron volts are used to measure subatomic particles.
- GeneralClass 12All
What is the formula for weight and mass?
The formula connecting weight and mass is: Weight = Mass × Gravitational acceleration or W = m × g Where: W = Weight (measured in Newtons) m = Mass (measured in kilograms) g = Gravitational acceleration (approximately 9.8 m/s² on Earth) This formula shows that weight depends on both mass and the local gravitational field.
- GeneralClass 12All
What is my mass if my weight is 60kg?
If someone says their "weight is 60 kg," they're actually referring to their mass, which is 60 kg. In everyday conversation, the terms are used interchangeably, though technically incorrect. Your actual weight in proper scientific units would be 588 Newtons (60 kg × 9.8 m/s²).
- GeneralClass 12All
What is my weight if my mass is 60kg?
If your mass is 60 kg, your weight on Earth is approximately 588 Newtons (60 kg × 9.8 m/s²). In everyday terms, people would say you "weigh 60 kg," but scientifically, your weight is the force of gravity acting on your 60 kg mass.
- GeneralClass 12All
Can I convert weight to mass?
Yes, you can convert weight to mass using the formula: Mass = Weight ÷ Gravitational acceleration or m = W ÷ g On Earth, divide the weight in Newtons by 9.8 m/s² to get mass in kilograms. However, if someone gives "weight" in kilograms, they're already referring to mass, as weight should be measured in Newtons.
- GeneralClass 12All
How do I calculate a mass?
To calculate mass, you can use several methods: From weight: Mass = Weight ÷ 9.8 (if weight is in Newtons) From density: Mass = Density × Volume Direct measurement: Use a balance or scale From force: Mass = Force ÷ Acceleration (Newton's Second Law) Choose the method based on available information and the context of your problem
- GeneralClass 12All
How to calculate total mass?
To calculate total mass, simply add together the masses of all individual components: Total Mass = Mass₁ + Mass₂ + Mass₃ + ... + Massₙ For example, if you have three objects with masses of 2 kg, 3.5 kg, and 1.2 kg, the total mass is 6.7 kg. Ensure all measurements are in the same unit before adding.
- GeneralClass 12All
Is mass equal to weight?
No, mass and weight are not equal. Mass measures the amount of matter in an object and remains constant everywhere. Weight measures the gravitational force acting on that mass and varies depending on location. For example, your mass stays the same on the Moon, but your weight is about one-sixth of what it is on Earth due to lower gravity.
- GeneralClass 12All
What is 1000 grams in mass?
1,000 grams equals 1 kilogram (1 kg) of mass. This is a fundamental conversion in the metric system and represents a common reference point for everyday mass measurements.
- GeneralClass 12All
How much mass is 1 gram?
One gram (1 g) is a unit of mass equal to one-thousandth of a kilogram (0.001 kg). It's approximately the mass of a small paperclip or a raisin. One gram equals 1,000 milligrams.