421. Select the best answer: Which wave requires a material medium to travel?
✅ C. Sound wave
Sound is a mechanical wave and requires a medium. Read more
Physics – Page 22
422. Select the best answer: What happens to the resistance of a metallic conductor generally when temperature increases?
✅ B. It increases
For typical metals, electrical resistance increases as temperature rises. Read more
423. Select the best answer: Which quantity is measured in joules?
✅ D. Energy
The joule is the SI unit of energy and work. Read more
424. Select the best answer: Which simple machine is a rigid bar pivoted about a fixed point?
✅ B. Lever
A lever is a rigid bar that rotates around a fulcrum. Read more
425. Select the best answer: What is momentum equal to?
✅ A. Mass × velocity
Linear momentum is p = mv. Read more
426. Select the best answer: Which phenomenon is the bouncing back of light from a surface?
✅ C. Reflection
Reflection is the return of light from a surface. Read more
427. Select the best answer: What is the unit of magnetic flux density?
✅ C. Tesla
Magnetic flux density is measured in teslas. Read more
428. Select the best answer: Which phenomenon explains the bending of light when it passes between media?
✅ D. Refraction
Refraction is the change in direction of light due to a change in speed between media. Read more
429. Select the best answer: What is frequency measured in?
✅ B. Hertz
Frequency is measured in hertz. Read more
430. Select the best answer: Which form of energy is stored in a stretched spring?
✅ D. Elastic potential energy
A stretched spring stores elastic potential energy. Read more
431. Select the best answer: What is the formula for kinetic energy?
✅ A. ½mv²
Kinetic energy is one-half mass times velocity squared. Read more
432. Select the best answer: What type of lens is thicker in the middle than at the edges?
✅ B. Convex lens
A convex lens is thicker at the center and converges parallel light rays. Read more
433. Select the best answer: What is the unit of electrical resistance?
✅ D. Ohm
Electrical resistance is measured in ohms. Read more
434. Select the best answer: Which law states that every action has an equal and opposite reaction?
✅ C. Newton's third law
Newton's third law describes action and reaction forces. Read more
435. Select the best answer: What instrument measures potential difference?
✅ B. Voltmeter
A voltmeter measures potential difference. Read more
436. Select the best answer: What is the acceleration due to gravity near Earth’s surface approximately?
✅ D. 9.8 m/s²
Near Earth's surface, gravitational acceleration is approximately 9.8 m/s². Read more
437. Select the best answer: What instrument measures electric current?
✅ A. Ammeter
An ammeter measures electric current. Read more
438. Select the best answer: What is the SI unit of pressure?
✅ D. Pascal
Pressure is measured in pascals. Read more
439. Select the best answer: What is the speed of light in vacuum approximately?
✅ A. 3 × 10^8 m/s
Light travels in vacuum at approximately 3 × 10^8 meters per second. Read more
440. Select the best answer: What is the SI unit of power?
✅ D. Watt
Power is measured in watts. Read more