Description : If you walk towards a plane mirror at a speed of 10 cm/s, at what speed does your image approach you? (a) 5 cm/s (b) 10 cm/s (c) 20 cm/s (d) Information inadequate
Last Answer : Ans:(c)
Description : A student focuses the image of a candle flame, placed at about 2 m from a convex lens of focal length 10 cm, on a screen. After that he moves gradually the flame towards the lens and each time focuses its ... d) What is seen on the screen when the flame is very close (at about 5 cm) to the lens?
Last Answer : (a) The student moves the lens away from the screen to focus the image because on moving the candle towards the lens, the image distance increases. (b)The size of the image increases when the object ... on the screen. A virtual image is formed behind the candle on the same side of the screen.
Description : A proton beam moves towards an observer. The direction of magnetic induction is a) towards right b) anticlockwise c) towards left d) clockwise
Last Answer : d) clockwise
Description : A particle of mass m moves in a circular path of radius r at constant speed v. Its KE is (a) mv2/r (b) ½ Iw (c) ½ mv2 (d) ½ mrw2
Description : A man is running away from a plane mirror at the speed of `5 ms^(-1)`. With what speed is he receding from his own image ?
Last Answer : A man is running away from a plane mirror at the speed of `5 ms^(-1)`. With what speed is he receding from his own image ?
Description : A boy is standing in front of a plane mirror at a distance of 3 m from it. What is the distance between the boy and his image? (1) 3 m (2) 6 m (3) 4.5 m (4) None of these
Last Answer : (2) 6 m Explanation: The image formed by a plane mirror is always virtual upright, and of the same shape and size as the object it is reflecting. A virtual image is a copy of an object formed at the location from which the light rays appear to come
Description : A rod at rest appears to an observer just a mere point when he moves across it as speed, a) Equal to the speed of light b) Double the speed of light c) Three-fourth the speed of light d) None of the above
Last Answer : a) Equal to the speed of light
Description : A white ball of mass 1.0 kg moving with initial speed u = 0.5 m s-1 collides with stationary red ball of same mass, they move forward making angle of 90° between their paths. Their speed is A. 1 m s-1 B. 0.354 m s-1 C. 2 m s-1 D. 3 m s-1
Last Answer : 0.354 m s-1
Description : A particle of mass M moves towards right with a velocity 2 V along the x-axis and another of mass 2 M with a velocity V towards left (- x axis). After the collision (they stick together on colliging) ... a.come to rest b.107 dynes c.move towards right d.may move in any direction e.move towards left
Last Answer : c. move towards right
Description : A mass of 5 kg moves on a smooth horizontal plane with a speed of 8 m/s attached to a fixed point on the plane by a string of length 4m. Tension in the string is a.785 b.80N c.392.4N d.None of the above e.Tapered bearing
Last Answer : b. 80N
Description : Where as a computer mouse moves over the table surface, the trackball is A) Stationary B) Difficult to move C) Dragged D) Moved in small steps
Last Answer : Answer : A
Description : Where as a computer mouse moves over the table surface, the trackball is a. Stationary b. Difficult to move c. Dragged d. Moved in small stems
Last Answer : a. Stationary
Description : A motor boat sails 30 km of a river towards upstream in 10hrs. How long will it take to cover the same distance downstream, if the speed of the current is ½ of the speed of the boat in still water. A) 1.8hrs B) 3.33hrs C) 5hrs D) None of these
Last Answer : ANSWER : B Explanation: Upstream speed = x –y Downstream speed = x + y x– y = 30/10 = 3km/hr Again x = 2y Therefore x – y = 3 y= 3km/hr ; x = 6km/hr Therefore x + y = 9 km/hr Time during downstream = 30/9 = 3.33hrs
Description : A particle moves along a rough plane inclined at 30? to the horizontal. The co-efficient of friction between the particle and the plane is 0.1. Its initial velocity is 15 m/sec. The ratio of the velocity of the particle when it move ... be in the regions a.8 ? 10 b.5 ? 7 c.2 ? 3 d.4 ? 6 e.10 ? 13
Last Answer : b. 5 ? 7
Description : A boy is standing in front of and close to a special mirror. He finds the image of his head bigger than normal, the middle part of his body of the same size, and his legs smaller than normal. The ... , Plane, Concave (b) Plane, Convex, Concave (c) Concave, Plane, Convex (d) Convex, Concave, Plan
Last Answer : (c) Concave, Plane, Convex
Description : If an electric field is applied to a colloidal sol, the dispersed phase particles are found to move towards the electrode of opposite charge. If however, the dispersed phase is made stationary, the ... move in the opposite direction. What is the term used for such movement of dispersion medium ?
Last Answer : Ans. Electro osmosis.
Description : A 250 m goods train takes 50 s to cross a person who is going in the same direction with the speed of 8 km/h. After crossing that person, the train can reach next station in 2 hr. How long that person takes to reach that station after being crossed by them? A) 2 ½ hr B) 5hr C) 3 1/2hr D) 1hr
Last Answer : ANSWER:A Explanation: Speed of the person = 8 kmph = (8*5/18)m/s = 20/9 m/s Then relative speed of train = (x-20/9)m/s As train takes 50 sec to cross the person Therefore 50 =250/(x-20/ ... 20,000 m = 20 km Thus time taken by the person to cover the distance of 20km= 20/8 hr=2 ½ hr
Description : A man is standing near the edge of a uniformly rotating platform about an axis passing through its centre. The speed of rotation of the platform will decrease if he a.extends his arms outwards b.moves ... heavy bag from one of his friends standing near by and holds it in his hand e.107 dynes
Last Answer : d. accepts a heavy bag from one of his friends standing near by and holds it in his hand
Description : A man is standing ner the edge of a uniformly rotating platform about an axis passing through its centre. The speed of rotation of the platorm will decrease if he a.extends his arms outwards b.107 ... towards the axis of rotation d.jumps out from that platform e.take out his coat and throws away
Last Answer : a. extends his arms outwards
Description : The term Blue Shift' is used to indicate? A. Doppler effect in which an object appears bluer when it is moving towards the observer or observer is moving towards the object? B. Turning a star from white ... . In future sun would become blue D. Black hole was blue at its start E. None of these
Last Answer : A. Doppler effect in which an object appears bluer when it is moving towards the observer or observer is moving towards the object?
Description : What type of mirror can be used to obtain the real image of an object? (a) Plane mirror (b) Concave mirror (c) Convex mirror (d) No mirror can produce a real image
Last Answer : Ans:(b)
Description : The image of an object formed in a plane mirror (a) is real (b) is virtual (c) can be obtained on screen (d) is slightly shorter than the object
Description : A six feet tall lady wants to see her full image in a plane mirror . The minimum length of the mirror will be ? A. 6 feet B. 12 feet C. 4 feet D. 3 feet (Answer) E. None of these
Last Answer : D. 3 feet (Answer)
Description : A real image of an object is to be obtained. The mirror required for this purpose is : (a) convex mirror (b) concave mirror (c) plane mirror (d) either convex or concave mirror
Last Answer : (c) plane mirror
Description : Which of the following is NOT true?Image formed by reflection through a plane mirror is a.of same size b.same orientation c.is at same distance from the mirror d.virtual
Last Answer : b.same orientation
Description : does a plane mirror produces a real image?
Last Answer : Real and "virtual" are two opposite, mutually exclusivecategories of images.An image is either one or the other, and no image can beboth.The image produced by a plane mirror is a virtual one.
Description : Where is the image formed in the plane mirror ?
Last Answer : The image is formed behind a plane mirror.
Description : The size of an image formed by a plane mirror is _____.
Last Answer : The size of an image formed by a plane mirror is _____. A. larger than the size of the object. ... the size of the object. D. Cannot be determined.
Description : The image formed by a plane mirror is ______ in nature.
Last Answer : The image formed by a plane mirror is ______ in nature.
Description : In a plane mirror the image is the same size as the object.?
Last Answer : Answer this question… In a plane mirror, the image is the samesize as the object.
Description : he image formed by a plane mirror is always
Last Answer : virtual and erect
Description : An image formed by a plane mirror, that cannot be obtained on a screen is called
Last Answer : Virtual image
Description : If you look into a mirror and find that the image (your reflexion) is smaller than you, then the type of the mirror is - (1) plano-concave mirror (2) concave mirror (3) plane mirror (4) convex mirror
Last Answer : (4) convex mirror Explanation: A convex mirror, diverging mirror, or fish eye mirror is a curved mirror in which the reflective surface bulges toward the light source. Such mirrors always form a virtual image and the image is smaller than the object.
Description : Which of the statements below correctly describes an achiral molecule? (a) The molecule has a nonsuperimposable mirror image. (b) The molecule exhibits optical activity when it interacts with plane-polarized light. (c) The molecule has an enantiomer. (d) The molecule might be a meso form
Last Answer : The molecule might be a meso form
Description : A molecule is said to be chiral (a) if it contains plane of symmetry (b) if it contains centre of symmetry (c) if it cannot be superimposed on its mirror image (d) if it can be superimposed on its mirror image
Last Answer : if it cannot be superimposed on its mirror image
Description : The size of the image formed by a plane mirror is a) bigger than the object b)same as object c)smaller than the object d)far away from the object .
Last Answer : b)same as object
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 : By which one of the following can a real image be produced? Can it be produced by a: w) concave mirror x) plane mirror y) diverging lens z) convex mirror
Last Answer : ANSWER: W -- CONCAVE 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)
Description : The noise from an airplane engine 100 ft from an observer is found to have an intensity of 45dB. What will be the intensity when the plane flies overhead at an altitude of 1 mi? A. 10.5 dB B. 34.5 dB C. 35 dB D. 20.5 dB
Last Answer : A. 10.5 dB
Description : Critical speed of rotation, N (in rps - rotation per second) of a trammel is equal to (where, g = acceleration due to gravity = 9.81 m/sec 2 and, r = radius of trammel, metre.) (A) (1/2π). √(g/r) (B) (1/π). √(g/r) (C) ½ √(g/r) (D) 2π. √(g/r)
Last Answer : (A) (1/2π). √(g/r)
Description : If h and h1 are the heights of a light house and the observer in a ship in metres above M S L then the horizontal distance from the ship to the light house in kilometres is (A) h + h1) (B) h - h1) (C) h × h1) (D) 3.86 h + h1)
Last Answer : (A) h + h1)
Description : A car starts from rest and moves on a straight road with a uniform acceleration of 10 m/s2 for the first 10 s. During the next 10 s, the car move s with the velocity it has attained. What is the total distance covered by the car in 20 s? (a) 500 m (b) 1000 m (c) 1,500 m (d) 2,000 m
Description : The area of a plane triangle ABC, having its base AC and perpendicular height , is (A) ½ bh (B) ½ ba sin C (C) ½ bc sin A (D) All the above
Last Answer : (D) All the above
Description : Write the code of signals used in ranging with respect to : i) Correct position ii) Fix the ranging rod iii) Vertical position of ranging rod iv) Move slowly to left of observer
Last Answer : i) Correct position : Both hands above Head and then Brought Down ii) Fix the ranging rod : Both Arms extended forward horizontally and the hands depressed briskly iii) Vertical position of ranging rod : 1 ... and moved to the Left iv) Move slowly to left of observer : Slow sweeps with Left Hand
Description : A train starts its journey from a stationary position and after running for 1 minute in parallel, 30 m / s speed is obtained. Determine the speed of the train in 1 minute ?
Last Answer : Here , the initial velocity , u = 0 m / s end velocity , v = 30 m / s time , t = 1 min = 60 sec we know , acceleration , a = (v- u) / t = (30- 0) / 60 = 0.5 m / s ^ 2 Acceleration = 0.5 m / s ^ 2
Description : Speed of stationary waves is A. 1 m s-1 B. 2 m s-1 C. 3 m s-1 D. zero
Last Answer : zero
Description : In an elastic collision between disks A and B of equal mass but unequal radii, A moves along the x-axis and B is stationary before impact. Which of th
Last Answer : In an elastic collision between disks A and B of equal mass but unequal radii, A moves along the x- ... @) and 60^(@)` with the x-axis respectively
Description : The change in flux linkages can be caused in which ofthe following ways ? (a) The flux is constant with respect to time and is stationary and the coil moves through it (b) The coil is stationary with ... above occure together, i.e., the coil moves through a time varying field (d) All ofthe above
Last Answer : (d) All ofthe above