WAVE!
What is formed when there is a changing Electric field ?
A. Electric wave C. Induced field
B. Magnetic field D. Magnetic Dipole
B. Magnetic field
Warm bodies emit what electromagnetic wave, and can be seen through thermal imaging?
INFRARED RADITATION
Light rays are represented by what illustration?
ARROW LINE
Which Lens is a CONVERGING LENS?
CONVEX LENS
---CONCAVE LENS IS DIVERGING
A bicycle light glowing when the wheel-mounted dynamo spins is an example of what device that convert movement into electricity?
Whose experiments confirms of the existence of electromagnetic waves?
A. Thomas Edison C. Heinrich Hertz
B. Michael Faraday D . Nikola Tesla
C. Heinrich Hertz
What makes microwaves more suitable than visible light in WIRELESS COMMUNICATION?
A. Microwaves travel faster than light waves.
B. Microwaves cannot penetrate the atmosphere.
C. Microwaves are less affected by weather conditions.
C. Microwaves are less affected by weather conditions.
A light ray bouncing off a mirror is called?
Reflected Ray
Light ray bends when entering from air into water. Why?
A. Light travels faster in water than in air.
B. Light slows down when entering a denser medium. C. The light ray changes direction randomly as it hits the surface.
D. Light reflects completely off the surface, not entering the water.
B. Light slows down when entering a denser medium.
Which part of the motor REVERSES the current flow?
COMMUTATOR
Which is TRUE among these statements?
A. Shorter wavelength and lower energy
B. Longer wavelength and lower energy
C. Shorter wavelength and higher energy
D. Longer wavelength and higher energy
C. Shorter wavelength and higher energy
Magnetic Resonance Imaging (MRI) uses ____ EMWave, while Computed Tomography Scan (CT Scan) uses ___ EMWave.
MRI - RADIOWAVE
CT SCAN - XRAY
What is the image formed by a PLANE MIRROR?
A. Virtual, inverted, and enlarged.
B. Real, inverted, and reduced.
C. Real, upright, and the same size as object.
D. Virtual, upright, and the same size as object.
D. Virtual, upright, and the same size as object.
You places a pencil behind a convex lens and observes that the image is inverted and smaller. Which is TRUE from the observation?
A. Light rays are reflected by the lens instead of passing through it.
B. The lens refracts light rays outward, causing them to diverge.
C. The lens refracts light rays inward, causing them to converge at a point.
C. The lens refracts light rays inward, causing them to converge at a point.
An electric generator ____, while an electric motor ________.
A. produces DC current; produces AC current.
B. is used for industrial purposes; is used for domestic purposes.
C. is driven by mechanical energy source; uses electricity to turn into mechanical energy.
D. converts electrical energy into mechanical energy converts mechanical energy into electrical energy.
C. is driven by mechanical energy source; uses electricity to turn into mechanical energy.
Why are high-frequency gamma rays more dangerous to humans than visible light? Gamma rays have ____
A. a lower frequency range than visible light.
B. a longer wavelength range than visible light.
C. less energy than visible light for penetrating matter.
D. greater energy than visible light for penetrating matter.
D. greater energy than visible light for penetrating matter.
How does FIBER OPTICS improves communication efficiency?
A. It uses LASER lights to deliver large amount of data.
B. It uses LASER lights to scatter information from source.
C. It uses LASER like sound waves, eliminating the need for physical cables.
A. It uses LASER lights to deliver large amount of data.
The mirror has a focal length of 20 cm. Using ray diagram techniques and mirror principles, where should you place the object to make a REAL, INVERTED AND MAGNEFIED image?
A. 10 cm in front of the mirror
B. 20 cm in front of the mirror
C. Beyond 40 cm in front of the mirror
D. Between 20 cm and 40 cm in front of the mirror
D. Between 20 cm and 40 cm in front of the mirror
Which eye defect occurs when light focuses BEHIND THE RETINA?
A. Nearsightedness C. Farsightedness
B. Cataracts D. Delusions
C. Farsightedness
Which principle is utilized by an electric generator to generate electricity?
A. Coulomb’s Law
B. Newton’s Law
C. Photoelectric Effect
D. Electromagnetic Induction
D. Electromagnetic Induction
WAVE X has a wavelength of 3.15×10⁻⁷ m. WAVE Z has a wavelength of 3.05X10⁻9 m.
WHICH IS TRUE?
a. WAVE X has higher energy because it has a longer wavelength.
b. WAVE Z has higher energy because its wavelength is shorter.
c. BOTH WAVES have equal energy since both are electromagnetic waves.
b. WAVE Z has higher energy because its wavelength is shorter.
Which part of the broadcasting system is responsible for converting electrical signals into radio waves?
A. antenna C. speaker
B. receiver D. transmitter
A. antenna
A curved mirror forms a virtual, upright, and smaller image when viewed from the front. What kind of mirror ALWAYS produce this type of image?
CONVEX MIRROR / DIVERGING MIRROR
What type of lens is used to correct NEARSIGHTEDNESS?
A. Converging C. Diverging
B. Achromatic D. Biconvex
C. Diverging
nearsighted - needs diverging lens
farsighted - needs converging lens
RECITE THE PARTS OF MOTOR / GENERATOR AND THEIR KEY WORDS.
STATOR - SET OF MAGNET
ROTOR - COILED WIRE
COMMUTATOR - METAL RING
BRUSH / TERMINAL - SMALL METAL SHEET