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When a light source is placed at the focus of a concave mirror, the rays of light that reflect off the mirror will emerge as a parallel beam of light. This happens because when a point source of light is placed at the focal point of a concave mirror, the reflected rays leave the mirror parallel to each other.

Given: u = -6 cm (the object is 6 cm from the eye, and the direction is negative), v = 10 cm (the image is 10 cm from the eye) Using the lens formula: \(\frac{1}{\text{f}}\) = \(\frac{1}{\text{v}}\) - \(\frac{1}{\text{u}}\) \(\frac{1}{\text{f}}\) = \(\frac{1}{10}\) + \(\frac{1}{6}\) \(\frac{1}{\text{f}}\) = \(\frac{8}{\text{30}}\) So that f = 3.75cm upon cross multiplying Therefore, the focal length of the lens is 3.75 cm.

When white light passes through a prism, dispersion occurs because different colors (wavelengths) of light travel at different speeds in the glass. This causes the colors to spread out and form a spectrum, with red bending the least and violet bending the most.

\(v = f\lambda\) \(v = 2f \times (l_{2} - l_{1})\) \(v = 2 \times 600 \times(0.413 - 0.130)\) \(v = 1200 \times 0.283\) \(v = 339.6ms^{-1}\)

As the vibrating tuning fork is brought closer to the end of the pipe, it causes the air column in the pipe to resonate. This resonance amplifies the sound waves, leading to an increase in loudness. The air column vibrates at specific frequencies, enhancing the sound produced by the tuning fork.

Harmonics are additional frequencies that accompany the fundamental frequency of a sound. Each instrument produces a unique harmonic spectrum, giving it a distinct timbre. This allows the ear to distinguish between notes played on different instruments, even at the same pitch. Pitch refers to the frequency of the sound. Speed is not a relevant factor in distinguishing instruments . Loudness relates to the intensity of sound, not its quality

The duality of matter refers to the concept in quantum mechanics that matter exhibits both wave-like and particle-like properties.

No expanded working has been attached for this question yet. The verified answer is Option B.

In a plane mirror, the image is formed as far behind the mirror as the object is in front of it. - The parade (object) is 6 m behind the man’s head. - The mirror is held 0.25 m in front of the man. So, the total distance from the parade to the mirror is: 6 m + 0.25 m = 6.25 m. The image will therefore appear 6.25 m behind the mirror. The man is looking into the mirror, so the distance from the man to the image is: Distance from man to mirror + Distance from mirror to image = 0.25 m + 6.25 m = 6.50 m Thus, the image of the parade appears to be 6.50 metres from the man.

Using the lens formula, \(\frac{1}{v} + \frac{1}{u} = \frac{1}{f}\) Where u, v and f are the object distance, image distance and focal length respectively. \(\therefore \frac{1}{2f} + \frac{1}{u} = \frac{1}{f}\) \(\frac{1}{u} = \frac{1}{2f} - \frac{1}{f} \implies \frac{1}{u} = \frac{1}{2f}\) \(u = 2f\) \(\therefore Magnification = \frac{\text{image distance}}{\text{object distance}}\) = \(\frac{2f}{2f}\) = 1

No expanded working has been attached for this question yet. The verified answer is Option E.

No expanded working has been attached for this question yet. The verified answer is Option D.

No expanded working has been attached for this question yet. The verified answer is Option D.

In a pinhole camera, a very small pinhole produces a sharp image because light rays from each point on the object pass through a single tiny opening and hit the screen in a small, focused area. When the pinhole is made larger, rays from the same object point can travel through different parts of the hole and spread out over a wider area on the screen. This results in blurred spots (larger circles of confusion) instead of sharp points, making the image less sharply defined. Although a larger pinhole allows more light and makes the image brighter, it sacrifices sharpness.

a)(i) Interference occurs in all kinds of waves i.e. longitudinal or transverse, while polarisation occurs only in transverse waves. (ii) - In sun glasses to reduce the intensity of light. - To produce polarised light. - To produce three dimensional pictures.