Ultrasound frequencies are typically above MCQ with Answer and Explanation

Ultrasound frequencies are typically above
A. 20000 Hz
B. 20 Hz
C. 2000 Hz
D. 200 Hz
Answer: Option A
Solution (By JKSSB Mock Tests)
Human hearing range is about 20 Hz to 20 kHz. Sound above 20 kHz is ultrasound. Infrasound is below 20 Hz. Ultrasound used in medical imaging (sonography), cleaning, SONAR.

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Practice More Physics Questions

Question #1
A car of mass 1000 kg moves with velocity 20 m/s. Kinetic energy is
A. 20 kJ
B. 10 kJ
C. 400 kJ
D. 200 kJ

Correct Answer: Option D


Explanation:
KE = ½×1000×400 = 200,000 J = 200 kJ.

This question belongs to: Science Physics
Question #2
Assertion (A): A convex mirror is used as a rear-view mirror in vehicles. Reason (R): A convex mirror always forms a virtual, erect, and diminished image, giving a wider field of view.
A. A is false but R is true.
B. Both A and R are true but R is NOT the correct explanation of A.
C. A is true but R is false.
D. Both A and R are true and R is the correct explanation of A.

Correct Answer: Option D


Explanation:
Convex mirrors bulge outwards, which inherently provides a much wider field of view compared to plane mirrors. Regardless of the object's position, a convex mirror reliably produces virtual, erect, and diminished (smaller) images. This allows a driver to see a large area of the road behind them in a small mirror, making R the exact explanation for A.

This question belongs to: Science Physics
Question #3
If the percentage error in measurement of radius of a sphere is 2%, the percentage error in volume is
A. 2%
B. 6%
C. 8%
D. 4%

Correct Answer: Option B


Explanation:
Volume V = (4/3)πr³, so ΔV/V = 3 Δr/r. Percentage error in volume = 3 × 2% = 6%.

This question belongs to: Science Physics