I. Say "True" if the statement is correct and "False" if wrong.
1. Magnetic field lines always flow from the North Pole to the South Pole outside the magnet.
2. Iron, cobalt and nickel are examples of magnetic materials.
3. The strength of magnetic field increases with distance from the magnet.
4. When connecting lamps in series, they will generally be brighter than if the same lamps were connected in parallel to the same voltage source.
5. Two parallel wires carrying currents in the same directions will attract each other.
II. Match the following from column B to A
6. Radio waves
7. Micro waves
8. Infrared
9. Visible light
10. Ultraviolet
11. X-rays
12. Gamma rays
A. Used in remote control & night vision cameras
B. Have the shortest wave length & highest energy.
C. Can cause sun burn, used in sterilization.
D. Emitted by stars, visible to the human eye.
E. Used in medical imaging to view inside the body.
F. Used to cook food & in radar system.
G. Longest wave length; used for communication
III. Choose the best answer from the given alternatives.
13. The image formed on the retina of a human eye is
A. Virtual & erect
B. Real & inverted
C. Real & erect
D. Virtual & inverted
14. Which of the following defects of vision is corrected using a concave lens?
A. Hypermetropia
B. Presbyopia
C. Myopia
D. Astigmatism
15. The least distance of distinct vision for a normal human eye is
A. 10cm
B. 25cm
C. 50cm
D. 100cm
16. Which optical instrument uses total internal reflection?
A. Periscope
B. Microscope
C. Telescope
D. Binoculars
17. Which of the following are the primary colors of light?
A. Red, yellow, blue
B. Red, green, blue
C. Cyan, magenta, yellow
D. Red, blue, black
18. Which color is subtracted when white light passes through a yellow pigment?
A. Red
B. Green
C. Blue
D. Magenta
Answer (2)
The answers provided above analyze statements about magnetic fields and properties of light, with explanations clarifying concepts like the behavior of magnets and the nature of light. Specific definitions, such as the primary colors of light and corrective measures for eyesight, help to reinforce understanding. The matching section connects different types of waves with their uses, providing further context.
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I. True or False Statements
True: Magnetic field lines always flow from the North Pole to the South Pole outside the magnet. This is a fundamental property of magnetic field lines.
True: Iron, cobalt, and nickel are examples of magnetic materials. These materials are known as ferromagnetic materials.
False: The strength of the magnetic field decreases with distance from the magnet. Magnetic field strength is strongest near the magnet and weakens as you move farther away.
False: When lamps are connected in series, they are generally dimmer than when connected in parallel to the same voltage source because the same current flows through each lamp, and the voltage across each is reduced.
True: Two parallel wires carrying currents in the same direction will attract each other. This is due to the magnetic forces between them.
II. Matching Column A with Column B
Radio waves - G. Longest wavelength; used for communication.
Microwaves - F. Used to cook food & in radar systems.
Infrared - A. Used in remote control & night vision cameras.
Visible light - D. Emitted by stars, visible to the human eye.
Ultraviolet - C. Can cause sunburn, used in sterilization.
X-rays - E. Used in medical imaging to view inside the body.
Gamma rays - B. Have the shortest wavelength & highest energy.
III. Multiple Choice Questions
The image formed on the retina of a human eye is: B. Real & inverted. The lens of the eye focuses light rays on the retina, forming a real and inverted image.
Which of the following defects of vision is corrected using a concave lens? C. Myopia. Concave lenses help in diverging light rays before they reach the eye lens, permitting light to focus on the retina.
The least distance of distinct vision for a normal human eye is: B. 25cm. This is the approximate distance at which the eye can focus on an object comfortably.
Which optical instrument uses total internal reflection? D. Binoculars. Binoculars use prisms to achieve total internal reflection, allowing for a compact, lightweight design.
Which of the following are the primary colors of light? B. Red, green, blue. These are the additive primary colors, used in digital screens and light mixing.
Which color is subtracted when white light passes through a yellow pigment? C. Blue. The yellow pigment absorbs blue light, leaving red and green, which together appear as yellow.
