Page 90 - CT&AI_CLasa_7_Part_1
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5. A dentist uses a concave mirror to examine 7. During a solar eclipse, students use a pinhole
a patient’s tooth. The tooth is placed very camera to observe the Sun. They notice that
close to the mirror, within its focal length. the image of the Sun on the screen is inverted
The dentist notices that the image is upright and smaller than the actual Sun. Which
and magnified, making examination easier. principle of light explains this observation?
Which principle explains this observation? (Abstract Thinking)
(Abstract Thinking)
(a) Light bends around corners,
making the image smaller.
(b) Light travels in straight lines,
forming a real, inverted and
smaller image through the pinhole.
(c) The pinhole increases the intensity
of light, making the image smaller.
(a) Concave mirrors always produce (d) The pinhole blocks most of the light,
inverted images. producing a faint shadow.
(b) Concave mirrors produce 8. In a cinema hall, a projector projects light
magnified, erect images when the onto a screen. When a person walks in front
object is within the focal length. of the beam, a their shadow appears on the
screen.
(c) Plane mirrors produce magnified
images at all distances.
(d) Convex mirrors are used to
magnify objects.
6. A kaleidoscope is made using three plane
mirrors inclined at 60° to each other.
When a child looks inside, she sees multiple
symmetrical patterns formed by colored
glass pieces. Why is the shadow sharp and clear?
Which principle of reflection explains the (Decomposition)
repeated patterns? (Pattern recognition)
(a) The person is translucent and
(a) Multiple reflections between
bends light.
inclined plane mirrors
(b) The person is opaque and blocks
(b) Random scattering of light by glass light travelling in straight lines.
pieces
(c) The projector enlarges the person’s
(c) Refraction of light through
transparent glass image on the screen.
(d) The screen absorbs all light falling
(d) Absorption of light by opaque
surfaces on it.
88 Computational Thinking-7 (Science)
