Fundamentals of Light, Electricity, and Magnetism : A Q&A Review

Fundamentals of Light, Electricity, and Magnetism : A Q&A Review 1. If the angle of incidence is 60° in a plane mirror, what is the angle of reflection? 2. LPG: butane CNG:_________ 3. Electric iron box: Nichrome Electric bulb: 4. Transformer: Mutual induction Moving Coil Microphone: 5. Calculate the effective resistance of 10 resistors of 42 connected in parallel. 6. Find the odd one out. (Reflection, Dispersion, Refraction, persistence of vision) 7. Which of the following is not a part of a loudspeaker? (Voice coil, Permanent magnet, Armature, Diaphragm) 8. What is the location of the LEDs in an LED bulb? 9. If a current of 0.4 A flows through an electric bulb operating at 230 volts, what is the power of the bulb? 10. What are the types of mirrors used in the following situations? (a) Vehicle rearview mirror (b) Shaving mirror (c) To see one's face 11. The calorific value of hydrogen is 1,50,000 kJ/kg. (a) What does this mean? (b) Hydrogen is not normally used as a domestic fuel. Why? 12. Write any three differences between bar magnet and solenoid. 13. The red of the setting sun and beautiful rainbows make nature colorful. a) Write the light phenomenon that causes a rainbow. b) Which color is found at the outer edge of a primary rainbow? Answers 1.the angle of reflection is also 60° 2.LPG (Liquefied Petroleum Gas) is primarily butane.CNG (Compressed Natural Gas) is primarily methane. 3.Electric bulb (incandescent) uses Tungsten as its filament. 4. Moving Coil Microphone works on the principle of Electromagnetic induction. 5. The effective resistance is 4.2 Omega 6. The odd one out is persistence of vision. 7. The component that is not a part of a loudspeaker is Armature. 8. The LEDs in an LED bulb are typically located on a circuit board (or array), which is then mounted inside the bulb's housing, often on an aluminum heat sink to dissipate heat. 9. The power of the bulb is 92 W. 10. ● ● ● 11. a) Vehicle rearview mirror: Plane mirror (or sometimes a slightly convex mirror for a wider field of view, though plane is standard for direct rearview) b) Shaving mirror: Concave mirror (to provide a magnified image) c) To see one's face: Plane mirror a) The calorific value of hydrogen being 1, 50,000 kJ/kg means that 150,000 kilojoules of heat energy are released when 1 kilogram of hydrogen is completely burned. b) Hydrogen is not normally used as a domestic fuel primarily due to storage and handling challenges, significant safety concerns related to its flammability, high production costs, and the lack of established infrastructure for its widespread domestic use. 12. . Magnetism: A bar magnet exhibits permanent magnetism, meaning its magnetic properties are inherent and constant. A solenoid's magnetism is temporary and dependent on the flow of electric current through its coils. . Control: The strength of a bar magnet's field is fixed. The strength of a solenoid's magnetic field can be varied by changing the current flowing through it or the number of turns in its coil. . Polarity: The poles of a bar magnet are fixed at its ends. The polarity of a solenoid can be reversed by changing the direction of the current flowing through it. 13. a) The light phenomenon that causes a rainbow is dispersion (the splitting of white light into its constituent colors), refraction (the bending of light as it passes from one medium to another), and internal reflection (light reflecting off the inner surface of the water droplet). b) The color found at the outer edge of a primary rainbow is red.