Understanding Intensity in Physics

What is the unit of intensity?

• Amperes per second

• Newtons per meter

• Watts per square meter

• Joules per second

How is intensity related to power and area?

• Intensity is power divided by area

• Intensity is area divided by power

• Intensity is power multiplied by area

• Intensity is area minus power

In the given problem, what is the power of the light bulb?

• 20 watts

• 50 watts

• 100 watts

• 200 watts

What shape does light form when spreading from a point source?

• Sphere

• Cube

• Cylinder

• Pyramid

What is the formula for the surface area of a sphere?

• 2πr

• 4πr²

• πr²

• 2πr²

What happens to intensity if the radius of the sphere decreases?

• Intensity becomes zero

• Intensity increases

• Intensity remains the same

• Intensity decreases

If the distance from the light source is doubled, what happens to the intensity?

• It remains the same

• It becomes one-fourth

• It halves

• It doubles

What is the relationship between intensity and distance from the source?

• Inversely proportional to the square of distance

• Directly proportional to distance

• Directly proportional to the square of distance

• Inversely proportional to distance

What is the intensity at a point 20 cm away from a 50-watt light bulb?

• 150 watts per square meter

• 99.5 watts per square meter

• 75 watts per square meter

• 50 watts per square meter

What is a common mistake when calculating intensity?

• Forgetting to square the distance

• Using the wrong units

• Using the wrong formula

• Forgetting to multiply by 4π