Description : Draw the ray diagram in each case to show the position and nature of the image formed when the object is placed: (i) at the centre of curvature of a concave mirror (ii) between the pole P and focus F of ... front of a convex mirror (iv) at 2F of a convex lens (v) in front of a concave lens -Physics
Last Answer : Answer. Nature of image: Real, inverted and same size image is formed at the centre of curvature. Nature of image: Virtual, enlarged and erect image is formed behind the mirror. Nature of image: Virtual ... : Virtual, erect and diminished image is formed between O and F on the same side of object.
Description : 147 A ray directed towards the centre of curvature of a spherical mirror a) become parallel to principal axis b)retraces its path c)appears to diverge from focus d)passes through focus.
Last Answer : b)retraces its path
Description : The distance between Pole and Focus is called a) principal axis b)focal length c)radius of curvature d)centre of curvature
Last Answer : b)focal length
Description : The focal length of a concave spherical mirror is equal to 1 meter. What is the radius of curvature of this mirror?
Last Answer : ANSWER: 2 METERS
Description : 2. The radius of curvature of a spherical mirror is 20 cm. What is its focal length? -Physics-10
Last Answer : Radius of curvature (R) = 20 cm Radius of curvature of the spherical mirror = 2 × Focal length (f) R = 2f f= R/2 = 20 / 2 = 10 Therefore, the focal length of the spherical mirror is 10 cm.
Description : The line joining the centre of curvature and pole of the mirror is called. ______.
Last Answer : The line joining the centre of curvature and pole of the mirror is called. ______. A. the principal axis B. y-axis C. the centre axis D. None of these
Description : To create an enlarged real image using a concave mirror, the object must be placed: w) beyond the center of curvature. x) between the center and the focus. y) at the focus. z) closer than the focus.
Last Answer : ANSWER: X -- BETWEEN THE CENTER AND THE FOCUS.
Description : A spherical convex surface separates object and image space of refractive index `1.0 and 4/3.` If radius of curvature of the surface is `10cm,` find i
Last Answer : A spherical convex surface separates object and image space of refractive index `1.0 and 4/3.` If ... of the surface is `10cm,` find its power.
Description : What reflecting surface forms a geometrically perfect image of a point source located at infinity (such as that approximated by a star)? w) Paraboloid x) Ellipsoid y) spherical z) Hyperboloid
Last Answer : ANSWER: W -- PARABOLOID
Description : What is the main focus of spherical mirror ?
Last Answer : : The point at which the rays of light parallel to the main axis of the spherical mirror meet at the point above the main axis (in the concave mirror) or appear to be moving away from the point above the main axis (in the convex mirror) is called the main focus of the spherical mirror.
Description : An object is placed beyond 2F, in front of a convex lens, image will be formed : (a) between F and 2F (b) at focus (c) at the centre of curvature (d) between focus and Optical centre
Last Answer : (a) between F and 2F
Description : 14. An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position, nature and size of the image. -Physics-10
Last Answer : Object distance (u) = - 20 cm Object height (h) = 5 cm Radius of curvature (R) = 30 cm Radius of curvature = 2 Focal length R = 2f f = 15 cm According to the mirror formula, ... image height indicates that the image formed is erect. Hence, the image formed is erect, virtual, and smaller in size.
Description : 1. Find the focal length of a convex mirror whose radius of curvature is 32 cm. -Physics-10
Last Answer : Radius of curvature (R) = 32 cm Radius of curvature = 2 × Focal length (f) R= 2f f = R/2 = 32/2 = 16 Therefore, the focal length of the given convex mirror is 16 cm.
Description : An object is placed at a distance of 12 cm in front of a concave mirror of radius of curvature 30 cm. List four characteristics of the image formed by the mirror. -Science
Last Answer : Here, radius of curvature of concave mirror, R = 30 cm. Therefore, focal length of the mirror, f = R/2 = 30/2 = 15 cm Also, object distance, u = 12 cm Hence, knowing the focal length of mirror and ... (i) Erect (ii) Larger in size than that of the object (iii) Virtual and (iv) Behind the mirror.
Description : A dentist concave mirror has a radius of curvature of `30 cm`. How far must it be placed from a small cavity in order to get a virtual image magnified
Last Answer : A dentist concave mirror has a radius of curvature of `30 cm`. How far must it be placed from a ... order to get a virtual image magnified `5` times ?
Description : An object is placed in front of a concave mirror of radius of curvature `40 cm` at a distance of `10 cm`. Find the position, nature and magnification
Last Answer : An object is placed in front of a concave mirror of radius of curvature `40 cm` at a ... Find the position, nature and magnification of the image.
Description : An object 0.04 m high is placed at a distance of 0.8 m from a concave mirror of radius of curvature 0.4 m. find the position, nature and the size of t
Last Answer : An object 0.04 m high is placed at a distance of 0.8 m from a concave mirror of radius of ... the position, nature and the size of the image formed.
Description : The radius of curvature of a converging mirror is 30 cm. At what distance from the mirror should an object be placed so as to obtain a virtual image? (a) infinity (b) 30 cm (c) Between 16 cm and 30 cm (d) Between 0 cm and 15 cm
Last Answer : (d) Between 0 cm and 15 cm
Description : The radius of curvature of the mirror is (a) -16 cm (b) -14 cm (c) -30 cm (d) -32 cm
Last Answer : (d) -32 cm
Description : If the radius of curvature of concave mirror is 12 cm. Then, the focal length will be : (a) 12 cm (b) 6 cm (c) -24 cm (d) -6 cm
Last Answer : (b) 6 cm
Description : Knot is a measure of – (1) The speed of ship (2) The curvature of spherical objects (3) Solar radiation (4) Intensity of earthquake shock
Last Answer : (1) The speed of ship Explanation: The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI).
Description : Knot is a measure of – (1) Unit of speed (2) the curvature of spherical objects (3) solar radiation (4) intensiry of earthquake shock
Last Answer : (1) Unit of speed Explanation: The Knot is a unit of speed equal to one nautical mile per hour. The ISO standerd symbol for the knot is Kn.
Description : Knot is a measure of (1) The speed of ship (2) The curvature of spherical objects (3) Solar radiation (4) Intensity of earthquake shock
Last Answer : The speed of ship
Description : An incident ray comes in parallel to the principle axis of a concave mirror. Is it reflected: w) back along the incident ray x) at 30 degrees to incident ray y) through the focal point z) through the center of curvature
Last Answer : ANSWER: Y -- THROUGH THE FOCAL POINT
Description : State the function of reflecting mirror in prismatic compass.
Last Answer : Function of reflecting mirror is to get image of an object located above or below the instrument level while bisection.
Description : The centre of a cyclone is a calm area and is called the_________ of the storm. a) Eye b) Focus c) Centre d) Radius
Last Answer : a) Eye
Description : What is the midpoint of the reflector surface of a spherical mirror called ?
Last Answer : The center point of the reflecting surface of a spherical mirror is called pole.
Description : The focal length of a plano-convex lens is 20 cm in air. Refractive index of glass is 1.5. Calculate (i) the radius of curvature of lens surface and (
Last Answer : The focal length of a plano-convex lens is 20 cm in air. Refractive index of glass is 1.5. ... length when immersed in liquid of refractive index 1.6
Description : The focal length of a double convex lens is equal to radius of curvature of either surface. The refractive index of its material is
Last Answer : The focal length of a double convex lens is equal to radius of curvature of either surface. The refractive index of its material is
Description : The following are true about the lens: a. the anterior capsule is 10 times thicker than the posterior capsule b. the anterior surface has a greater radius of curvature than the posterior surface c ... the cornea d. the lens is more effective in absorbing light with long than short wave-lengths
Last Answer : during accommodation the lens moves towards the cornea
Description : The sensitiveness of a level tube decreases if (A) Radius of curvature of its inner surface is increased (B) Diameter of the tube is increased (C) Length of the vapour bubble is increased (D) Both viscosity and surface tension are increased
Last Answer : (D) Both viscosity and surface tension are increased
Description : The maximum value of hoop compression in a dome is given by (A) wR / 4d (B) wR/2d (C) wR/d (D) 2wR/d Where, w = load per unit area of surface of dome R = radius of curvature d = thickness of dome
Last Answer : (B) wR/2d
Description : What is a spherical mirror ?
Last Answer : If the reflecting surface is smooth and spherical, that is, if the reflecting surface is a special part of a sphere and there is regular reflection of light in it, then it is called spherical mirror.
Description : The mirror used for the head light of a car is – (1) spherical concave (2) plane (3) cylindrical (4) parabolic concave
Last Answer : (4) parabolic concave Explanation: A parabolic (or paraboloid or paraboloidal) reflector(or dish or mirror) is a reflective surface used to collect or project energy such as light, sound, or radio waves.
Description : A real image can be formed by which of the following single mirrors? w) a plane mirror x) a concave spherical mirror y) a convex spherical mirror
Last Answer : ANSWER: X -- A CONCAVE SPHERICAL MIRROR
Description : A virtual image can be formed by one or more of the following single mirrors? Identify them. w) plane mirror x) concave spherical mirror y) convex spherical mirror z) all of the above
Last Answer : ANSWER: Z -- ALL OF THE ABOVE (accept: A, B and C)
Last Answer : The radius of curvature of the lens is two.
Description : According to standard convention, the angles of incidence and reflection for a plane surface are measured from: w) the reflecting surface x) lines at 45 degrees to the reflecting surface y) a line at 90 degrees to the reflecting surface z) there is no standard
Last Answer : ANSWER: Y -- A LINE AT 90 DEGREES TO THE REFLECTING SURFACE
Description : Assume a ray of light is incident on a smooth reflecting surface at an angle of incidence of 15 degrees to the normal. What is the angle between the incident ray and the reflected ray?
Last Answer : ANSWER: 30 DEGREES
Description : The radius of a spherical balloon increases from 7cm to 14cm as air is being pumped into it. Find the ratio of surface areas of the balloon in the two cases. -Maths 9th
Last Answer : Let r1 and r2 be the radii of spherical balloon and spherical balloon when air is pumped into it respectively. So r1 = 7cm r2 = 14 cm Now, Required ratio = (initial surface area)/(Surface area after pumping air into ... = (7/14)2 = (1/2)2 = ¼ Therefore, the ratio between the surface areas is 1:4.
Description : A spherical ball is divided into two equal halves. If the curved surface area of each half is 56.57 cm?, find the volume of the spherical ball.11531/cylinder-radius-halved-and-height-doubled-then-find-volume-with-respect-original-volume -Maths 9th
Last Answer : since curved surface of half of the spherical ball = 56.57 cm2 ∴ 2πr2 = 56.57 ⇒ r2 = 56.57 / 2 × 3.14 = 9 ⇒ r = 3 cm Now, volume of spherical ball = 4 / 3 πr3 = 4 / 3 × 3.14 × 3 × 3 × 3 = 113.04 cm3
Description : A spherical metal of radius 10 cm is melted and made into 1000 smaller spheres of equal sizes. In this process the surface area of the -Maths 9th
Last Answer : Option (C) is correct. Solution: Let the radius of the small spheres be r' cm. Volume of metal remains the same in both cases. So, vol of the spherical metal of radius 10 cm = total ... Total Surface area of 1000 smaller spheres: 1000*4π12 = 4000π Hence, the surface area increased by 10 times.
Description : The volume of a spherical balloon is increasing at a rate of ` 25 cm^(3)//sec`. Find the rate of increase of its curved surface when the radius of bal
Last Answer : The volume of a spherical balloon is increasing at a rate of ` 25 cm^(3)//sec`. Find the ... its curved surface when the radius of balloon is 5 cm.
Description : The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) (A) K/h0 (B) 2K/h0 (C) h0 /K (D) h0 /2K
Last Answer : (B) 2K/h0
Description : A spherical porous catalyst particle of radius R is subjected to reactant A which reacts to form B by a zero order surface reaction A → B. Film mass transfer resistance is negligible and pore diffusion of A ... (D) Effectiveness factor for a zero order reaction cannot be 7/8 as it must always be 1
Last Answer : (A) Inner catalyst core of radius R/8 does not participate in reaction (
Last Answer : The center of a spherical mirror from which light is reflected is called the pole of the mirror.
Description : A first order reaction A → B occurs in an isothermal porous catalyst pellet of spherical shape. If the concentration of A at the centre of the pellet is much less than at the external surface, the ... A) Diffusion within the pellet (B) Reaction (C) External mass transfer (D) None of the above
Last Answer : (A) Diffusion within the pellet
Description : How does a waveguide-type lens focus spherical wavefront microwave energy?
Last Answer : Some wavefronts are accelerated so that all wavefronts exit the lens at the same time
Description : The gravitational field intensity is maximum at the a.107 dynes b.at a height above the surface c.pole d.equator e.centre of the earth
Last Answer : e. centre of the earth