Define the principal focus of a concave mirror.
ScienceClass 10CBSEAnswered 27 Mar 2026
Answer
Answer-
Light rays that are parallel to the principal axis of a concave mirror converge at a specific point on its principal axis after reflecting from the mirror. This point is called the principal focus of the concave mirror.
Suggested Q&A
Science · Class 10- ScienceClass 10Define power of a lens. What is its unit? One student uses a lens of focal length 50 cm and another of – 50 cm. What is the nature of the lens and its power used by each of them?
- ScienceClass 10Size of image of an object by a mirror having a focal length of 20 cm is observed to be reduced to 1/3rd of its size. At what distance the object has been placed from the mirror? What is the nature of the image and the mirror?
- ScienceClass 10Find the focal length of a convex mirror whose radius of curvature is 32 cm.
- ScienceClass 10Why do we prefer a convex mirror as a rear-view mirror in vehicles?
- ScienceClass 10Name the mirror that can give an erect and enlarged image of an object.
- ScienceClass 10The radius of curvature of a spherical mirror is 20 cm. What is its focal length?
- ScienceClass 10Explain the following. a. Why is the tungsten used almost exclusively for filament of electric lamps? b. Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal? c. Why is the series arrangement not used for domestic circuits? d. How does the resistance of a wire vary with its area of cross-section? e. Why copper and aluminium wires are usually employed for electricity transmission?
- ScienceClass 10An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.
- ScienceClass 10Which uses more energy, a 250 W TV set in 1 hr, or a 1200 W toaster in 10 minutes?
- ScienceClass 10How is a voltmeter connected in the circuit to measure the potential difference between two points?