Basic Physics Questions and Answers

4 D A small electric dipole is placed in x y plane at origin with its dipole moment directed alone positive x axis The direction of electric field point 2 2 2 0 is 1 Along positive z axis 2 Along positive y axis 3 Along negative y axis 4 Along negative z axis

A harmonic pressure wave produced by a distant source is travelling through your vicinity and wavefronts that travel through your vicinity are vertical planes Let x direction is to be east and y direction be toward north The wave function of wave is p x y t Acos kx ky ot y A Direction of wave propagation is at an angle 0 cot k ky B Direction of wave propagation is at an angle 0 tan k X C Wave speed is D Wave speed is k k with x axis with x axis

A calorimeter contains ice Q 500 Cal of heat is required to heat it together with its contents from 270 K to 272 K and Q 16 600 Cal from 272 K to 274 K If heat capacity of the calorimeter is 25z Cal C find the value of z Lice 80 Cal g Specific heat of ice 0 5 Calg C and that of water 1 Cal g C System is at normal atmospheric pressure

A current is flowing through a conducting hollow pipe whose area of cross section is shown in the figure The value of magnetic induction will be zero at R Q P O Point P Q and R O Point R but not at P and Q Point Q but not at P and R O Point P but not at Q and R

4 The total charge of the universe is n If an object contains n protons and the net charge on the object is 2 n n e 4 Zero is placed near another charge 1 n n e 3 n n e spherical conductor Th electrons surface g Two identic supported contact Wh on X and rod is brou 1 X will

1 2 A body of mass 1 kg is projected with velocity 50 ms at an angle of 30 with the horizontal At the highest point of its path a force 10 N starts acting on body for 5 s vertically upward besides gravitational force what is horizontal range of the body Take g 10 ms 2 125 3 m b 200 3 m c 500 m 250 3 m

3 Arrange the following rays in the increasing order of their wavelength Xrays Ultra violet rays Visible rays Infra red rays 1 Infra red rays Visible rays Ultra violet rays X rays 2 Visible rays Infrared rays X rays Ultra violet rays 3 Ultra violet rays X rays Infra red rays Visible rays 4 X rays Ultra violet rays Visible rays Infra red rays

37 A stone of mass m is tied to a string of length at one end and by holding second end it is whirl into a horizontal circle then work done by tension when it covers half revolution will be 1 O 2 mv m 2 2 l 3 mg 2 l 4 mv l

Four children were asked to arrange forces due to rolling static and sliding frictions in an increasing order Their arrangements are given below Choose the correct arrangement A Rolling Static Sliding C Rolling sliding static B Static Rolling Sliding D Sliding Static Rolling for several months The

I am having difficulties with conversion of u nits of speed So please give the formulas f or the following conversions i m s to km hr and vice versa ii cm s to m s and vice versa iii cm min to m s and vice versa iv cm min to km hr and vice versa

4 An Electric light fixture weighing 15N hangs from a point C by two strings AC and BC AC is inclined at 60 to the horizontal and BC at 45 to the vertical as shown in figure Determine the forces in the strings AC and BC A B 45 T F 450 30 C E 60 T

36 A light ray falls on a plane mirror and deviates by 60 then the angle of reflection will be 1 30 2 60 3 90 4 180 37 A stone of mass m is tied to a string of length at one end and by holding second end it is whirle into a horizontal circle than work dong hu tansion when it covers half rouolution will be

2 A uniform magnetic field B 3 4j k T exists in a region of space A section of conductor between point 2 0 and 5 0 which is as shown carries a current of 2 A in xy plane The magnetic force on the conductor in newton will be y m 4 1 3 i 4k 3 6 j 4k 2 5 x m 2 6 i 4k 4 7 i 4k

Two blocks of equal mass are tied with a light string which passes over a massless pulley as sho In figure The magnitude of acceleration of centre of mass of both the blocks is neglect fricti everywhere B 3 1 4 2 602 g 2 3 1 g 3 1 2 4 g 8 D 20 60 30

uestion Light propagates rectilinearly because a 1 Frequency

2 a 3 An apple is falling freely near the surface of the Earth If a is the magnitude of acceleration of apple and an is the magnitude of acceleration of earth then choose the correct statement a2 is much greater than a 0 and a 0 4 a 1 a is much greater than 3 a is equal to a2

A current loop of area 0 05 m and carrying a current of 4 A is held perpendicular to a magnetic field induction of 0 5T then torque acting on the loop is A 0 01 N m YOU B 0 1 N m c 1 N m

Due to manufacturing defect the plane surface of a thin plano concave lens has been made tilted at a small angle outwards from its usual place The spherical surface has radius of curvature R and refractive index of the material of the lens is u A parallel beam of light is incident as shown In the Co ordinate system shown find the co ordinates of the point where the rays will focus or appear to be diverging from X

D Write True or False in front of statements given below 1 The movement of an object is called force 2 A force can change the shape or size of an object 3 Bodies can move without the application of force 4 The force acting on a windmill is gravitational force 5 The force exerted by the earth on the bodies is called pressure

English Review Q If both the mass and the radius of the earth decrease by 1 the value of the acceleration due to gravity will Question Type Single Correct Type 1 decrease by 1 2 increase by 1 3 increase by 2 4 remain unchanged

Q24 An e m e enters 1 to a uniform E field with speed V as shown Find the vertical deflection y of er and angle at which it emerges out of field 0 Assume the space to be gravity free 2 D Motion x M V AO S X t t L y U O a F eE HE SO x s y F OF E

Question 32 Equal current r flows in two segment of circular loop as shown in figure Radius of the loop is a Magnetic field at the centre of the loop due to segment ACB is C Options X DI Ko 20 Bot 2 0 Ho 2n 20 B

The displacement of a particle moving in a straight line is described by the relation s 6 12t 2t2 Here s is in metre and t is in second The distance covered by particle first 5 s is a 20 m d 26 m 1 A train acceleratie b 32 m c 24 m

32 33 34 35 36 37 38 39 40 Decayver 350 100 Decay rate for a certain mass of a radioactive substance measured at diffrent times varies with time as shown in fig countrate at t 8 hr will be 50 Question Type Single Correct Type 25 2 decays sec 2 50 decays sec English 3 500 decays sec 750 decays sec Review de 42

of the particle Length of a minute hand of a clock is 4 5 cm Find the average velocity of the tip of minute s hand bet 6 A M to 6 30 A M 6 A M to 6 30 P M

A player A plays a game against a machine At each round he deposits one rupee in a slot and then flips a coin which has a probability p of showing a head If a head shows he gets back the rupee he deposited and one more rupee from the machine If a tail shows he loses his rupee Let A starts with 10 rupees and q 1 p 7 8 9 The probability that he is left with no money by the tenth round or earlier is a glo b d 10 r l a q10 1 10 pq 45p q b q 4 p q 36pq 7 c q 3pq 3 3p q p d g 0 1 10 pq 65p q 10 q 10 C p q10 r c pq The probability that all his money will be finished exactly at the twelfth round is 1 plo a q 2 b 1 pl c C pq d 12C p q The probability that he is left with no money by the 14th round or earlier is

Rubbing your hands together warms them by converting work into thermal energy If a woman rubs her hands back and forth for a total of 12 rubs at a distance of 7 50 cm per rub and with a frictional force of 40 0 N what is the temperature increase in degrees Celslus The mass of tissue warmed is only 0 100 kg mostly in the palms and fingers

strikes on the sphere The maximum electric potential of the sphere will be hc 12400 eV 1 4 6 V 2 6 2 V 3 1 6 V 4 3 2 V In a long cylindrical tube the water level is adjusted and the air column above it is made to vibrate in unison with a vibrating tuning fork kept at the open end Maximum sound is heard when the air column lengths are equal to 2 2 3A 32 42 4 3 2 32 52 22 2 2 2 4 32 52 4 4 4 34 um ducea RICHE YEART Sexual T aften fan fava ami hc 12400 eV 2 6 2 V 4 3 2 V VE SE V for for 1 4 6 V 3 1 6 V 2 1 3 3 4 2 4 32 52 22 2 2 4 2 3 214 4 4 A 32 52 4 4 afazia af and

A block of mass 25 kg is being dragged across a frictionless surface by a rope with an unknown tension See diagram The block starts from rest and travels 30 m in 6 s Calculate the tension in the rope rope 35

If AxB 3A B then the value of A B is AIIMS 2000 CBSE PMT 2004 J K CET 2008 Odisha JEE 2012 1 2 4 3 48 AB b A B 3 c A B 3AB 2 d A B AB 2 a

a The temperature of a can of soda was 25 C Lisa puts this can of soda in the freezer to cool off quickly but forgets to take it out If the current temperature of the can is 12 C how much did the temperature of the can drop by Official test question R test que

2 The diagram shows the energy levels for an electron certain atom Which transition shown represent emission of a photon with the most energy 170 insluvres I II III IV b III IV c II n 4 n 3 n 2 n 1 d I

While measuring the surface tension of a liquid by a capillary of non uniform bore its radius should be measured O at the lower end dipped in liquid at the upper end open in air O by taking mean of the radii at the two ends O by cutting the capillary at the point up to which the liquid rises in the capillary 4

In a vernier calipers 50 divisions of vernier scale coincides with 47divisions of main scale There is no zero error in the device When an object of length 7 62 mm is placed between the lower jaws of the calipers 25 N division of main scale exactly coincides with Mh division of vernier scale Find N Given value of 1 main scale division is 1 mm and number of vernier scale divisions is 50 O DO 8 Clear Response

15 Two rings of same mass and radius R are placed with their planes perpendicular to each other and centres at a common point The radius of gyration of the system about an axis passing through the x centre and perpendicular to plane of one ring is ENE 2R M 4 3R

11 The emf of the battery shown in figure is 252 202 12 1 12V 3 18V TE www 60 25 VIA 2 16V 4 1SV 192

A boy pushes a toy box 2 0 m along the floor by means of a force of 10 N directed downward at an angle of 60 to the horizontal The work done by the boy is a 6J b 8 J 2020 c 10 J d 12 J

AB is a chord of the circle x y 25 The tangents to the circle at A and B intersect at C If 2 is the mid point of AB then the area of quadrilateral OACB is 50 3 13 C 50 3 3 A B 50 D 50 13

If the law were changed so that traffic in India travelled on the right hand side of the road instead of on the left what would happen to the length of the day A Slightly increase C Will remain unaltered B Slightly decrease D Can t be said

A small steel sphere tied at the end of a string is whirled in a horizontal circle with uniform angular velocity The string is suddenly pulled so that the radius of the circle is halved If w is the new angular velocity then O 0 0 001 O O w w w 001

N Q42 The resultant of two perpendicular vectors makes 30 with one of them AO 2 3 What is the possible ratio of magnitudes of the original vectors L

According to Kirchhoff s law the algebraic sum of product of current and resistance as well as e m f in a closed loop is O zero O determined by the e m f O greater than zero 1 poi

A light wooden rod fixed at one end is kept horizontal A load of 0 4 kg tied to the free end of the rod causes that end to be depressed by 2 8 cm If this load is set into up and down vibrations with what frequency will it oscillate

A 2 F capacitor is charged to 100 V After disconnecting the battery a 20 mH coil is then connected across the charged capacitor The capacitor discharges through the inductor and the current in the circuit is oscillatory Maximum current in the circuit assuming zero resistance of the coil is 0 5 A O 0 75 A 1 A

34 A ray of light is incident at an angle of incidence i on one face of a prism of angle A assumed to be small and emerges normally from the opposite face If the refractive index of the prism is p the angle of incidence i is nearly equal to A A a A b MA 2 c d 2 5 The damping force on an oscillator is directly proportional to the velocity The units of the constant of proportionality are b kg m s 2 kg m s VAIDUAL CAMERA Jign 150mariean Macher The two C Ba gat a b c W 3021 08 13 17

Q 41 If A 10 A AO 10 2 10 and B 5 then A B BO 5 5 13 B

Two infinite parallel non conducting sheet carry equal positive charge density o One is placed in y z plane and other at distance x a Take potential V 0 at x o A For 0 x a potential v 0 0 B For x a potential v Eo C For x a potential v D x 0 potential v x x a x a Eo

E Solve the following problems An explosion was heard by two Police stations 1200 m apart located at F 600 0 an F2 600 0 If the explosion was heard in F two seconds before it was heard in I identify the possible locations of the explosion Use 340 m s as the speed of sound

3 78 A heavy particle of mass m is in motion on a smooth surface of a hemisphere of radius R and there is no friction At the initial instant the particle is at the topmost point A and has an initial velocity vo At what point will the particle leave the surface of the hemisphere Also determine the value of vo for which the particle will leave the sphere at the initial instant Ans 0 cos 2 vo 3 3gR gR

A ball is thrown with speed v and angle of projection with horizontal is If the coefficient of restitution between ball and horizontal plane is e then the horizontal distance travelled by the ball after long time will be Select an answer u sin 0 A 8 B u sin 0 Cu cos 0 g D 1 e None of these