Total Questions: 50
• Sonar uses sound propagation to navigate, measure distances. communicate with or detect objects on or under the surface of the water.
• He was born on February 15, 1564, in Pisa.
• He was an Italian physicist, astronomer, philosopher, and mathematician.
• Electrical devices like Electric fuse, electric iron, electric toaster, and electric heater are based on the principle of Joules law.
• The reason for more scattering of blue colour is that the wavelength of the blue light is shorter than the other light.
• So blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere.
• Radius of Curvature R is the radius of the sphere of which the mirror is a part.
• Focal length and radius of curvature are related as:f = R/2
(i) Soft iron core
(ii) Coll
(iii) Magnets
• The coil is mounted on an axIe and is placed between the cylindrical concave poles of a magnet.
• The commutator is used to reverse the direction of flow of current.
• if we stretch the thumb, forefinger, and the middle finger of the left-hand perpendicular to each other, then the forefinger indicates the direction of the magnetic field, the middle finger denotes the direction of current and the thumb represents the direction of the force.
So, from the above diagram it is clear that AB is incident ray and CD is an emergent ray.
• In other words, m= v/u, where v is the image distance and u is the object distance
• So, m=30/25 = 6/5
• In convex lens, the real image is inverted hence its magnification is negative.
So, m = - 6/5
