This question tests understanding of refraction. When light travels from air (lower refractive index) to water (higher refractive index), the light speed decreases because v = c/n, where water's higher n means lower speed. At the air-water boundary, the wave component parallel to the interface must remain continuous, but the overall speed reduction causes the ray to bend toward the normal. This behavior is described by Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where water's larger n₂ requires a smaller refraction angle θ₂. Choice C incorrectly suggests frequency increases, but frequency is determined by the source and never changes during refraction. The fundamental rule is: waves bend toward the normal when they slow down (entering a denser medium).

This question tests understanding of refraction. When light travels from plastic (n = 1.49) to air (n ≈ 1.0), the light speed increases because v = c/n, where air's lower n means higher speed. At the plastic-air boundary, maintaining continuity of the parallel wave component while the overall speed increases causes the ray to bend away from the normal. This follows Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where air's smaller n₂ requires a larger angle θ₂ from the normal. Choice D incorrectly claims frequency decreases, but frequency remains constant across material boundaries—only speed and wavelength change. Remember: when light speeds up (entering a less dense medium), it always bends away from the normal.

This question tests understanding of refraction. When light travels from water (higher refractive index) to mineral oil (lower refractive index), the light speed increases because v = c/n, where oil's lower n means higher speed. At the water-oil boundary, the parallel component of the wave maintains continuity, but the overall speed increase causes the ray to bend away from the normal. This follows Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where oil's smaller n₂ results in a larger angle θ₂ from the normal. Choice C incorrectly claims frequency increases, but frequency is determined by the source and remains constant during refraction. The transferable principle is: when light speeds up (entering a less dense medium), it always bends away from the normal.

This question tests understanding of refraction. When light travels from glass (higher refractive index) to glycerin (lower refractive index), the light speed increases because v = c/n, where a lower n means higher speed. At the boundary, the wave component parallel to the interface maintains its speed, but the overall wave speed increase causes the ray to bend away from the normal. This behavior follows Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where the smaller n₂ results in a larger refraction angle θ₂. Choice D incorrectly suggests frequency changes, but frequency remains constant across material boundaries—only speed and wavelength change with the medium. Remember: when light speeds up (entering a less dense medium), it bends away from the normal.

This question tests understanding of refraction. When light travels from a medium with higher refractive index (water) to one with lower refractive index (air), the light speed increases because v = c/n. As the wave crosses the boundary, the parallel component of velocity must remain continuous, but since the overall speed increases in air, the wave must bend away from the normal to accommodate this speed change. This follows from Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where the smaller n₂ (air) requires a larger θ₂ (angle from normal). Choice C incorrectly claims frequency changes, but frequency is determined by the source and remains constant during refraction. The transferable principle is: when light enters a medium with lower refractive index (faster speed), it always bends away from the normal.

This question tests understanding of refraction. When light travels from diamond (higher refractive index) to air (lower refractive index), the light speed increases since v = c/n and air has a much smaller n. At the boundary, maintaining continuity of the parallel wave component while the overall speed increases causes the ray to bend away from the normal. This follows from Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where air's smaller n₂ requires a larger angle θ₂ from the normal. Choice D incorrectly claims frequency decreases, but frequency remains constant across boundaries—it's determined by the source, not the medium. The key strategy is: when light speeds up (entering a less dense medium), it always bends away from the normal.

This question tests understanding of refraction. When light travels from ethanol (lower refractive index) to glass (higher refractive index), the light speed decreases since v = c/n and glass has a larger n. At the boundary, the wave's parallel component maintains continuity, but the overall speed decrease causes the ray to bend toward the normal. This follows Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where the larger n₂ (glass) requires a smaller angle θ₂ from the normal. Choice D incorrectly claims frequency changes, but frequency is an intrinsic property of the light source and remains constant during refraction. The key principle is: when light slows down (entering a denser medium), it always bends toward the normal.

This question tests understanding of refraction. When light travels from air (n ≈ 1.0) to a liquid with n = 1.60, the light speed decreases significantly because v = c/n. At the air-liquid boundary, the wave's parallel component must maintain continuity, but the overall speed reduction causes the ray to bend toward the normal. This is quantified by Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where the liquid's larger n₂ = 1.60 requires a much smaller refraction angle θ₂. Choice C incorrectly suggests frequency increases, but frequency is an intrinsic property of the light source that never changes during refraction. The key strategy is: waves bend toward the normal when they slow down (entering a denser medium).

This question tests understanding of refraction. When light travels from air (lower refractive index) to crown glass (higher refractive index), the light speed decreases because v = c/n, where glass's higher n results in lower speed. At the air-glass boundary, the wave's parallel component maintains continuity, but the overall speed reduction causes the ray to bend toward the normal. This is described by Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where glass's larger n₂ requires a smaller refraction angle θ₂. Choice C incorrectly suggests frequency increases, but frequency is an invariant property during refraction—only wavelength and speed change with the medium. Remember: waves bend toward the normal when they slow down (entering a denser medium).

This question tests understanding of refraction. When light travels from a medium with lower refractive index (air) to one with higher refractive index (acrylic), the light speed decreases because v = c/n, where n is the refractive index. At the boundary, the component of the wave parallel to the interface must maintain the same speed, but since the overall wave speed decreases, the perpendicular component must decrease more, causing the ray to bend toward the normal. This bending toward the normal when entering a denser medium follows Snell's law: n₁sin(θ₁) = n₂sin(θ₂), where the larger n₂ requires a smaller θ₂. Choice C incorrectly suggests frequency changes, but frequency remains constant across boundaries—only wavelength and speed change. The key strategy is: when light enters a medium with higher refractive index (slower speed), it always bends toward the normal.