SECTION – I (Total Marks : 50) Single Correct Answer Type There are five parts in this question. Four choices are given for each part and one of them is correct. Indicate you choice of the correct answer for each part in your answer-book by writing the letter (a), (b), (c) or (d) whichever is appropriate
01 Problem A hollow metallic sphere of radius 10 cm is charged such that potential of its surface is 80 V. The potential at the centre of the sphere would be 80 V 800 V zero 8 V.
Problem 02 Charge q2 is at the centre of a circular path with radius r. Work done in carrying charge q1, one around the equipotential path, would be a. b. c. zero d. infinite.
Problem 03 A magnet oscillates, in earth’s magnetic field, with a time-period T. If its mass is quadrupled, then its new time – period will be T/2, motion remaining S.H.M Unaffected but motion is not S.H.M. 4T, motion remaining S.H.M. 2T, motion remaining S.H.M.
Problem 04 The given figure gives electric lines of force due to two charges q1 and q2. What are the sings of the two charges? q1 is positive but q2 is negative q1 is negative but q2 is positive both are negative both are positive.
Problem 05 A circular loop of area 0.01 m2 carrying a current of 10 A, is held perpendicular to a magnetic field of intensity 0.1 T. The torque acting on the loop is N .m 0.8 N.m zero N.m
Problem 06 An electric bulb is rated 60 W, 220 V. The resistance of its filament is 870 780 708 807
Problem 07 Two cables of copper are of equal lengths. One of them has a single wire of area of cross- section A, while other has 10 wires of Cross-sectional area A/10 each. Give their suitability for transporting A.C. and D.C. Only multiple strands for A.C., either for D.C. Only multiple strands for A.C., only single strand for D.C. Only single strand for D.C., either for A.C. Only single strand for A.C., either for D.C.
Problem 08 An L-C-R circuit is connected to a source of A.C. current, At resonance, the phase difference between the applied voltage and the current in the circuit, is a. b. zero c. /4 d. /2
Problem 09 A wire 50 cm long and 1 mm2 in cross –section carries a current of 4 A when connected to a 2 V battery. The resistivity of the wire is
4 x 10-6 1x 10-6 2x 10-7 5 x10-7 .
Problem 10 Six resistors of 3 each are connected along the sides of a hexagon and three resistor of 6 each are connected along AC, AD and AE as shown in the figure. The equivalent resistance between A and B is equal to 2 6 3 9
Problem 11 A small source of light is 4 m below the surface of water of refractive index 5/3. In order to cut off all the light, coming out of water surface, minimum diameter of the disc placed on the surface of water is a. 6 m b. c. 3m d. 4m
Problem 12 In an A.C. circuit, Irms and andI0 and related as a. b. c. d.
Problem 13 Identify the set in which all the three materials are good conductors of electricity Cu, Hg and NaCl Cu, Ge and Hg Cu, Ag and Au Cu, Si and diamond.
Problem 14 A flow of 107 electrons per second in a conducting wire constitutes a current of 1.6 x 10-12 A 1.6 x 1026 A 1.6 x 10-26 A 1.6 x 1012 A.
Problem 15 The current I in an A.C. circuit inductance coil varies with time according to the graph given below. Which one of the following graphs gives the variation of voltage with time? a. b. c. d.
Problem 16 A source of frequency v gives 5 beats/second when sounded with a source of frequency 200 Hz. The second harmonic of frequency 2v of source gives 10 beats/second when sounded with a source of frequency 420 Hz. The value of v is 205 Hz 195 Hz. 200 Hz 210 Hz.
Problem 17 I A loaded vertical spring executes S.H.M. with a time period of 4 sec. The difference between the kinetic energy and potential energy of this system varies with a period of 2 sec 1 sec 8 sec 5sec
Problem 18 Which of the following is simple harmonic motion? Particle moving in a circle with uniform speed Wave moving through a string fixed at both ends Earth spinning about its axis Ball bouncing between two rigid vertical walls.
Problem 19 Ray optics is valid, when characteristic dimensions are
Much smaller than the wavelength of light Of the same order as the wavelength of light Of the order of one millimeter Much larger than the wavelength of light.
Problem 20 Which of the following electromagnetic radiations have the smaller wavelength ? X-rays y-rays UV waves Microwaves.
Problem 21 The blue colour of the sky is due to the phenomenon of
Scattering Dispersion Reflection Refraction.
Problem 22 Which one of the following gates correspond to the truth table given below? NAND NOR XOR OR
Problem 23 An electric dipole of moment p is placed in the position of stable equilibrium in uniform electric field of intensity E. This is rotated through an angle from the initial position. The potential energy of the electric dipole in the final position is -pEcos pE (1- cos ) pEcos pE sin .
Problem 24 In an adiabatic change, the pressure and temperature of a monatomic gas are related as where C equals a. b. c. d.
Problem 25 For lenses of focal length 15 cm and 150 cm are available for making a telescope. To produce the largest magnification, the focal length of the eyepiece should be + 15 cm + 150 cm 150 cm -15 cm.
Problem 26 A stationary wave is represented by where y and A are in millimeters, t is in second and x is meters. The velocity of the wave is 104 m/s not derivable 1 m/s 102 m/s
Problem 27 The oscillating electric and magnetic vectors of an e.m. wave are oriented along Mutually perpendicular directions and are in phase Mutually perpendicular directions but has a phase difference of 900 The same direction and are in phase The same direction but have a phase difference of 900
Problem 28 The displacement –time graph of a moving particle is shown below. The instantaneous velocity of the particle in negative at the point E F C D
Problem 29 A solid spherical ball rolls on a table. Ratio of its rotational kinetic energy to total kinetic energy is a. b. c. d.
Problem 30 A particle executes S.H.M along x-axis. The force acting on it is given by A cos (kx) Ae-kx Akx Akx.
Problem 31 Two identical balls A and B collide head on elastically. If velocities of A and B, before the collision, are +0.5 m/s and –0.3 m/s respectively, then their velocities, after the collision, are respectively -0.5 m/s and + 0.3 m/s + 0.5 m/s and + 0.3 m/s + 0.3 m/s and – 0.5 m/s -0.3 m/s and + 0.5 m/s.
Problem 32 A seconds pendulum is mounted in a rocket. Its period of oscillation will decrease when rocket is Moving down with uniform acceleration Moving around the earth in geostationary orbit Moving up with uniform velocity Moving up with uniform acceleration. Decline
Problem 33 A wave of frequency 100 Hz travels along a string towards its fixed end. When this wave travels back, after refection, a node is formed at a distance of 10 cm from the fixed end. The speed of the wave (incident and reflected ) is 20 m/s 40 m/s 6m/s 10 m/s.
Problem 34 A body of mass 5 kg hangs from a spring and oscillates with a time period of 2 seconds. If the ball is removed, the length of the spring will decrease by g/k meters k/g meters 2 meters g meters.
Problem 35 Which one of the following represents a wave? a. b. c. d.
Problem 36 In a rocket, fuel burns at the rate of 1 kg/s. This fuel is ejected from the rocket with a velocity of 60 km/s. This exerts a force on the rocket equal to
6000 N 60000 N 60 N 600 N
Problem 37 A satellite in force – free space sweeps stationary interplanetary dust at a rate of where M is mass and v is the speed of satellite and is a constant. The acceleration of satellite is a. b. c. d.
Problem 38 If the gravitational force between tow objects were proportional to 1/R (and not as 1/R2), where R is the distance between them, then a particle in a circular path (under such a force ) would have its orbital speed v, proportional to R R0(independent of R) 1/R2 1/R.
Problem 39 The distance of two planets from the sun are 1013 m and 1012 m respectively. The ratio of time periods of the planets is a. b.10 c. 10 d.1/
Problem 40 The radius of earth is about 6400 km and that of mars is 3200 km. The mass of the earth is about 10 times mass of mars. An object weighs 200 N on the surface of earth. Its weight on the surface of mars will be 20 N 6N 80N 40 N
Problem 41 When a body moves with a constant speed along a circle
No work is done on it No acceleration is produced in it Its velocity remains constant No force acts on it
Problem 42 The velocity of train increases uniformly from 20 km/h to 60 km/h in 4 hours. The distance traveled by the train during this period is 160 km 180 km 100 km 120 km.
Problem 43 A position dependent force, F = 7 –2x + 3x2 N acts on a small body of mass 2 kg and displaces if from the work done in joules is 135 270 35 70.
Problem 44 A particle moves along a straight line such that its displacement at any time t is given by meters. The velocity when the acceleration is zero is 3 m/s 42 m/s -9 m/s -15 m/s.
Problem 45 a boat is sent across a river with a velocity of 8 km/h. If the resultant velocity of boat is 10 km/h, then velocity of the river is 8km/h 10km/h 12.8 km/h 6 km/h.
Problem 46 A car accelerates from rest at a constant rate for some time after which it decelerates at a constant rate and comes to rest. If total time elapsed is t, then maximum velocity acquired by car will be a. b. c. d.
Problem 47 The kinetic energy acquired by a mass m in traveling distance d. starting from rest, under the action of a constant force is directly proportional to a. m b. c. d.1/
Problem 48 A body, constrained to move in y-direction, is subjected to a force given by The work done by this force in moving the body through a distance of m along y-axis, is 150 J 20 J 190 J 160 J
Problem 49 The angle between the two vectors and will be 900 1800 zero 450.
Problem 50 Which of the following has the dimensions of pressure?