A pointed tip helps in the easy discharge of electric charge into the air due to the concentration of charge at the sharp end. This prevents the buildup of large charges, reducing the chances of a lightning strike on the building.
Related Questions:
- Two parallel straight conductors carrying current in the same direction attract each other? Explain why. What will you conclude if the direction of current in conductors is opposite?
- Bar magnets are dropped in long pipes made up of plastic and copper (of the same length) simultaneously. The bar magnet comes out later through the copper pipe than through the plastic pipe. Why?
- What is the direction of rotation of the coil (shown in the figure) when the switch is closed? Label the diagram with the direction of forces forming a couple and the rotation of the coil.
- A bar magnet is moving near a ring. What is the direction of the induced current in the ring when:
- Why is the output of a transformer zero if DC voltage is applied to its primary coil?
- Why are coils of a transformer wound on an iron core?
- Why is step-up transmission used for long-distance transmission?
- When you push a bar magnet towards a single-turn coil, you feel an opposing force. If the magnet is pushed towards a coil with many turns, why is the opposing force greater?
- How do split rings (commutators) in a DC motor differ from slip rings in an AC motor?
- Why does a charged balloon stick to a wall even though the wall is neutral?
- Why does a person feel a small electric shock after walking on a carpet and then touching a metal object?
- Why does a lightning conductor have a pointed tip?
- Numerical Problems – Chapter 15: Electromagnetism
- Discuss the magnetic field produced around a straight current-carrying conductor. State and explain the rule by which the direction of the lines of force of the magnetic field around a current-carrying conductor can be determined.
- What is a solenoid? Discuss the magnetic field due to a current-carrying solenoid. How can you find the direction of its field?
- Why is force applied on a current-carrying conductor in an external magnetic field? Write its formula. What are the different factors on which this force depends? State the rule by which the direction of this force can be found.
- Why is torque applied on a current-carrying coil placed in a magnetic field? Discuss in detail. What are the factors on which torque depends?
- What is a DC motor? Describe its construction and working in detail.
- Define electromagnetic induction. Describe a simple experiment to demonstrate that a changing magnetic field can produce emf.
- Show that induced current and induced emf in a circuit follow the law of conservation of energy.