EmSAT Physics — Questions and Answers
Question 1: According to Newton's Second Law of Motion, what happens to acceleration if the net force is doubled while mass remains constant?
- Acceleration is halved
- Acceleration is doubled (Correct answer)
- Acceleration remains the same
- Acceleration is quadrupled
Correct answer: Acceleration is doubled
Newton's Second Law states F = ma. If force doubles and mass stays constant, acceleration must also double since a = F/m.
Question 2: What is the SI unit of electrical resistance?
- Ampere
- Volt
- Ohm (Correct answer)
- Watt
Correct answer: Ohm
The ohm (Ω) is the SI unit of electrical resistance, named after Georg Simon Ohm. It is defined as the resistance between two points when one volt produces one ampere of current.
Question 3: What type of energy transformation occurs in a solar panel?
- Kinetic to thermal
- Light (radiant) to electrical (Correct answer)
- Chemical to kinetic
- Nuclear to thermal
Correct answer: Light (radiant) to electrical
Solar panels (photovoltaic cells) convert light energy (electromagnetic radiation from the sun) into electrical energy through the photovoltaic effect.
Question 4: What is the speed of a car that travels 150 km in 3 hours?
- 450 km/h
- 50 km/h (Correct answer)
- 30 km/h
- 153 km/h
Correct answer: 50 km/h
Speed = distance / time = 150 km / 3 hours = 50 km/h.
Question 5: Which of the following is an example of a longitudinal wave?
- Light wave
- Water wave
- Sound wave (Correct answer)
- Radio wave
Correct answer: Sound wave
Sound waves are longitudinal waves where the particles of the medium vibrate parallel to the direction of wave propagation, creating compressions and rarefactions.
Question 6: What is the relationship between wavelength and frequency for electromagnetic waves?
- They are directly proportional
- They are inversely proportional (wavelength × frequency = speed of light) (Correct answer)
- They are equal
- There is no relationship
Correct answer: They are inversely proportional (wavelength × frequency = speed of light)
For electromagnetic waves, c = λf, where c is the speed of light (constant). As frequency increases, wavelength decreases proportionally, making them inversely proportional.
EmSAT Physics
According to Newton's Second Law of Motion, what happens to acceleration if the net force is doubled while mass remains constant?