10th class Physics: model paper 1 (objective)
BISE Lahore pattern · 12 MCQs in 15 min
This is a model paper written by Parcha, not an official BISE Lahore paper. For the board's own past papers, use its website.
Official past papers on the BISE Lahore websiteObjective part (MCQs)
Q1 · Parcha original · Sample
The time period of a simple pendulum depends on:
- A. The mass of the bob
- B. The amplitude (for small swings)
- C. The length of the pendulum
- D. The material of the string
Show answer
Answer: C. The length of the pendulum
For small swings, T = 2π√(l/g): the period depends only on the length l and the acceleration due to gravity g, not on the mass of the bob or the amplitude.
Open this question on its own pageQ2 · Parcha original · Sample
The SI unit of frequency is the:
- A. Hertz
- B. Second
- C. Metre
- D. Newton
Show answer
Answer: A. Hertz
Frequency is the number of vibrations per second; 1 hertz (Hz) = 1 vibration per second = 1 s⁻¹. The second is the unit of the time period.
Q3 · Parcha original · Sample
In simple harmonic motion, the acceleration of the body is:
- A. Constant
- B. Directly proportional to displacement and opposite to it
- C. Inversely proportional to displacement
- D. Always zero
Show answer
Answer: B. Directly proportional to displacement and opposite to it
SHM is defined by a = −(constant) × x: acceleration is proportional to displacement from the mean position and always directed towards it. It is greatest at the extremes and zero at the mean position.
Q4 · Parcha original · Sample
Waves transfer:
- A. Matter only
- B. Both matter and energy
- C. Neither matter nor energy
- D. Energy, without carrying matter along
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Answer: D. Energy, without carrying matter along
In a wave, the particles of the medium only vibrate about their positions; it is the energy that travels onward. A floating leaf bobs up and down as water waves pass but does not travel with them.
Q5 · Parcha original · Sample
Sound waves travelling through air are:
- A. Transverse waves
- B. Electromagnetic waves
- C. Longitudinal waves
- D. Stationary waves
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Answer: C. Longitudinal waves
Air particles vibrate back and forth along the direction the sound travels, forming compressions and rarefactions: longitudinal waves. Sound needs a medium; electromagnetic waves do not.
Q6 · Parcha original · Sample
A wave has a frequency of 50 Hz and a wavelength of 2 m. Its speed is:
- A. 25 m/s
- B. 100 m/s
- C. 52 m/s
- D. 0.04 m/s
Show answer
Answer: B. 100 m/s
v = fλ = 50 × 2 = 100 m/s.
Q7 · Parcha original · Sample
Sound travels fastest in:
- A. Steel
- B. Water
- C. Air
- D. A vacuum
Show answer
Answer: A. Steel
Sound is fastest in solids, slower in liquids and slowest in gases: roughly 5,000 m/s in steel, 1,500 m/s in water and 340 m/s in air. It cannot travel through a vacuum at all.
Open this question on its own pageQ8 · Parcha original · Sample
The audible frequency range for a normal human ear is about:
- A. 2 Hz to 2,000 Hz
- B. 200 Hz to 200,000 Hz
- C. 20 Hz to 20,000 Hz
- D. 0 Hz to 2 Hz
Show answer
Answer: C. 20 Hz to 20,000 Hz
People with normal hearing hear about 20 Hz to 20,000 Hz (20 kHz). Below 20 Hz is infrasound; above 20 kHz is ultrasound.
Q9 · Parcha original · Sample
Ultrasound has frequencies:
- A. Below 20 Hz
- B. Between 20 Hz and 2,000 Hz
- C. Exactly 20 kHz
- D. Above 20 kHz
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Answer: D. Above 20 kHz
Ultrasound is sound above the upper limit of human hearing, 20 kHz. It is used in medical scans, cleaning and sonar.
Q10 · Parcha original · Sample
The loudness of a sound depends mainly on its:
- A. Frequency
- B. Amplitude
- C. Wavelength alone
- D. Speed
Show answer
Answer: B. Amplitude
A larger amplitude carries more energy, so the sound is louder. Frequency decides the pitch, not the loudness.
Q11 · Parcha original · Sample
The pitch of a sound depends on its:
- A. Frequency
- B. Amplitude
- C. Loudness
- D. Quality
Show answer
Answer: A. Frequency
Higher frequency means higher pitch: a whistle sounds shrill because of its high frequency. Amplitude affects loudness, and the mix of overtones gives quality (timbre).
Q12 · Parcha original · Sample
To hear a distinct echo in air (speed of sound 340 m/s), the reflecting surface must be at least about how far away?
- A. 34 m
- B. 10 m
- C. 17 m
- D. 170 m
Show answer
Answer: C. 17 m
The ear keeps a sound for about 0.1 s, so the echo must return after at least 0.1 s. In 0.1 s sound travels 340 × 0.1 = 34 m there and back, so the surface must be at least 17 m away.