Basic Physics Questions and Answers

49 Below figure shows a mass m suspended with a massless inextensible string passing over a frictionless pulley The spring constant is K what is the time period of oscillations of the mass fat fo mh Ran a ford fed dr un yn adu fed y pulley 331 f f f 1 2 m 2K 2 2 m K G TA eeeeeeee K T m Img 3 2 2m K 4 2 2m 3K

50 A long conducting wire AH is moved over a conducting triangular wire CDE with a constant velocity V in a uniform magnetic field B directed into the plane of the paper Resistance per unit length of each wire is p Then A C F G B E H 1 Induced emf in the loop remains constant 2 Induced emf increases with time 3 Induced emf decreases linearly with time 4 May increase or decrease

man is sitting on the shore of a river He is in the line of a 10 m long boat and is 5 5 m away from the centre of the boat He wishes to throw an apple into the boat If he can throw the apple only with a speed of 10 m s find the minimum and maximum angles of projection for successful shot Assume that the point of 5

ring of mass 2m and radius R is set into pure rolling on horizontal rough surface in a uniform magnetic field of strength B as shown in the figure A point charge q of negligible ass is attached to rolling ring Friction is sufficient so that it does not slip at any point of its motion 0 is measured in clockwise from positive y axis YA x x x x2mx x x x x XXX XXX 9x xx xx x XXXXX 0 xxxx XX X R X XX

A three dimensional motion of an object is given by the vector function UTM r t 4 costi 4 sint j 5 k 37 Sketch the motion of the object when 0 t and the velocity vector of the object when t 7 2

A small electric dipole is placed at origin with its dipole moment directed along positive x axis The direction of electric field at point 2 2 2 0 is A along z axis B along y axis c along negative y axis

In young s experiment a mica sheet of refractive index 1 5 and thickness 6 x 10 6 m is placed in the path of one of interfering beams as a result of which the central fringe gets shifted through five fringe width The wave length of light used is TH G Nhi t goi ch gi HT 1 5 37dd tich 72ll 6 106 TT Hi u L ch 3734 i tote Taff at fi 1 6000 3 4000 4 2000 2 8000

In a given vernier callipers ten parts of varnier scale are equal to nine parts of main scale If each part of main scale is of 0 1 cm than what will be least count of vernier calliper charter affer 10 944 af you 1 0 01 cm L ch HT ch l ch 0 1 cm 2 0 1 cm 3 0 001 cm 4 0 05 cm

6 The freezing point on a thermometer is marked as 20 degree and the boiling point as 130 degree A temperature of human body 34 degree Celsius on this thermometer will be read as O 31 degree O 51 degree O 20 degree O None of these

42 4 400 uH At an instant current in this network is potential difference between points A and ind current is increasing at 1A sec 1 15V 3 1V Awwwww 5A 12 15V voooo 5H 2 25V 4 10V ne B Fram

3 t 4 unit 4 t 0 unit 9 When a bar magnet falls through a long hollow m cylinder fixed with its axis vertical then acceler of the magnet when it is accelerating will be 1 Zero 2 More than g 3 Less than g 4 Equal to g

A charge Q is placed next to a conducting spherical shell with no excess charge it a Draw the electric field lines and charges in space including the cavity in the sphere b Now the outside of the shell is grounded Draw the electric field lines and charges in space including the cavity in the sphere Explain what grounding does O Q

8 A block of mass 10 kg is kept at rest on a rough inclined surface as shown g 10 m s 10kich geet 3rd ed The net contact force on m is 1 80 N 2 60 N m 0 75 37 3 40 N 4 100 N

In a particular system the units of length mass and time are chosen to be 10cm 10g and 0 1s respectively The unit of force in this system will be equivalent to 1 0 1N 3 10N 2 1N 4 100N

Aakash Institute 54 A closed conducting loop is moved towards right with retardation as shown in the figure The induced current in the loop will be to 1 Clockwise and increasing with time 2 Clockwise and decreasing with time 3 Anti clockwise and increasing with time

4 To a spring whose constant is 90 lb ft there is attached a 7 pound weight This is drawn 3 in below the equilibrium point and projected upward with a speed of 12 ft sec Find two forms for the equation of the motion What is the period

16 Why is mercury used in thermometers OIts volume is proportional to square of increase of temperature OIt shows linear variation in volume with temperature Its volume remains constant with temperature Its volume decreases with increase in temperature

4 If S is stress and Y is Young s modulus of material of a wire the energy stored in the wire per unit volum is 1 2 52V ucured quis su ar ufa sis 3 fan 3 S 2 2 2Y 0 S

121 Two electric bulbs rated 50 W and 100 W are glowing at full power when used in parallel with a battery of emf 120 V and internal resistance 100 The maximum number of bulbs that can be connected in the circuit when glowing at full power is a 6 b 4 d 8 c 2

A rod of mass M and length L is lying on a horizontal frictionless surface A particle of mass m travelling along the surface hits at one end of the rod with a velocity u in a direction perpendicular to the rod The collision is completely elastic After collision particle comes to rest The ratio of masses m M is 1 x The value of x will be

3 i A physical quantity X is connected X a b c Calculate the percentage error in X when error in a b c are 4 2 and 3 respectively ii Percentage error in the measurement of height and radius of cylinder are x and y respectively Find the percentage error in the measurement of volume Which of the two measurements height or radius needs more attention

The focal length of a suitable convex lens is 30 cm ar the size of image is quarter of the object Then object distance from lens is 150 cm 60 cm 30 cm 40 cm

0 A vibration magnetometer consists of two identical bar magnets placed one over the other such that they are perpendicular and bisect each other The time period of oscillation in a horizontal magnetic field is 2 sec One of the magnets is removed and if the other magnet oscillates in the same field then the time period in second is 1 2 3 2 2 4 als C

A symmetric double convex lens is cut into two equa parts by a plane perpendicular to the principle axis If the power of the original lens was 4 D then the power of each part of cut lens will be 2 D 3 D 4 D O 5D

circuit between terminals a b Where R1 R3 R5 10 2 R2 0 R420 2 and R6 20 2 Also S1 is 10V S2 is 2A and S3 is zero volt R R www R3 S3 R5 www Ry

Identify whether the objects in the given situations possess Potential Energy or Kinetic Energy Write your answers on a separate sheet of paper 1 Bird flying 2 Log in a fireplace 3 Watermelon on a desk 4 Car travelling on the highway 5 Car sitting in a driveway 6 Bunch of coconut stick on a table 7 Ball bouncing on the floor 8 Child jumping on his bed 9 Child sleeping on the crib 10 Marble rolling down the ramp

The transition from the state n 3 ton 1 in a hydrogen like atom results in ultraviolet radiation Infrared radiation will be obtained in the transition from F 1 42 1 a Barch for 2 4 3 3 21 4 3 2

The amplitude of wave disturbance propagating in 1 the positive x direction is given by y 1 x 1 1 x 2 at time t 0 and y and y are in meres The shape of wave does not change during the propagation The velocity of the waye will be m s at t 1s where x

Light travels through a glass plate of thickness t and refractive index n If c is the velocity of light in vacuum then time taken by the light to travel this thickness of glass is t nc tnc Ont c tc n

20 In tan A position of a deflection magnetometer a short magnet placed at 10 cm from the centre produces at deflection of 30 If another short magnet of dipole moment sixteen times the previous magnet is kept at 20 cm from the centre in tan B position the deflection will be 1 60 3 30 2 45 4 0

Aakash Institute 35 Two magnetic isolated north poles each of strength in ampere meter are placed one at each of two vertices of an equilateral triangle of side a The resultant magnetic induction at third vertex is 1 3 Hom 4x a Ho 3m 2 2 4 Ho 2m 4x a 15 E

InCorrect Question No 2 Photoelectric effect experiments are performed using three different metal plates p q and r having work functions 2 0 eV 2 5 eV and 3 0 Options UnAnswer eV respectively A light beam containing wavelengths of 550 nm 450 nm and 350 nm respectively with equal intensities illuminates each of the plates The correct I V graph for the experiment is Take hc 1240 eV nm

A quarterback takes the ball from the line of scrimmage runs backward for 19 yards then runs sideways parallel to the line of scrim mage for 17 yards At this point he throws a 36 yards forward pass straight downfield perpendicular to the line of scrimmage What is the magnitude of the football s resultant displacement Answer in units of yards

5 According to Gauss law in magnetism Bds equal to 1 Zero 2 Positive 3 Negative 4 Positive negative or zero Telegram

23 Consider a thin metallic sheet perpendicular to the plane of the paper moving with speed v in a uniform magnetic field B going into the plane of the paper see fig If charge densities a and are induced on the left and right surfaces respectively of the sheet then ignore fringe effects 1 a 2 a 3 a VB XXX XXX X X X X X X xx xx xx xx xx xx xx xx xx 5 VB 2 5VB 2 2 VB VB E VB vB 2

Two conducting planes are located at x 0 and x 65 mm The zero reference voltage is at x 45 mm Given that E 145 x V m The voltage of the conductor at x 0 is O a 6 52 V O b 32 62 V O c 16 31 V O d 16 31 V O e 6 52 V O f 65 25 V O g 32 62 V Oh 65 25 V

A 9 900 9 bullet is fired into a stationary block of wood having mass m 5 070 kg The bullet imbeds into the block The speed of the bullet plus wood combination immediately after the collision is 0 5920 m s What was the original speed of the bullet Express your answer with four significam figures 1

109 Find the equivalent resistance across AB A Bo 2022 222 www www 2Q2 2222 222 RA 8R B b 222 Ja 12 c 32 d 42 110 The equivalent resistance between P and Q in

40 A magnetic needle lying parallel to magnetic field requires W unit of work to turn it through 60 The torque needed to maintain the needle in this final position will be 1 3w 3 3w 2 2 W 4 2W

54 A heavy cart is pulled by a constant force F along a horizontal track with the help of a rope that passes over a fixed pulley as shown in the figure Assume the tension in the rope and the frictional forces on the cart remain constant and consider motion of the cart until it reaches vertically below the pulley F As the cart moves to the right its acceleration A decreases B increases C remains constant D is zero

A dip circle is taken to geomagnetic equator The needle is allowed to move in a vertical plane perpendicular to the magnetic meridian The needle will stay a in horizontal direction only b in vertical direction only c in any direction except vertical and horizontal d in any direction it is released

3 1 5 sec 4 2 0 sec 2 The magnetic moment produced in a substance of 1g is 6 x 10 7 Am If its density is 5g cm then the intensity of magnetisation in A m will be 1 8 3 x 106 2 3 0

A container of square base of side and height H is completely filled with a liquid of density p And it is closed with the help of a square plate AD of side 1 This plate has a vertical tube of radius r and height h volume of the tube is negligible as compared to volume of the liquid at its centre and a small hole at D Just after giving a horizontal acceleration a g 2 towards right find out B B 28 4 h 2g 49 Velocity of the liquid flowing out though the tube if h 1 5 neglect surface tension of the liquid A gl C 8 7 D 2g 11th 2 a g 2

It is de a The is for Aakash Institute 15 Two magnets placed one above the other oscillates with a period of 6 sec If one of them is reversed the time period becomes 2 sec The ratio of their magnetic moment is nearest to 1 3 2 54

As per the diagram a point charge q is placed at the origin O Work done in taking another point charge Q from the point A coordinates 0 a to another point B coordinates a 0 along the straight path AB is a zero b 9Q 1 4 an 2 a c A O 9Q 1 1 4 a y 2 a B

A 100 V voltmeter of internal resistance 20 k in series with a high resistance Rx is connected to a 110 V line The voltmeter reads 5 V the value of Rx is A 210 k B 315 k C 420 kN D 440 kn Rx www 20 10 Q V 110 V 5 V

For the motion of a particle attached to a string in vertical circle at what location tension is maximum The motion is under the influence of gravity and tension alone 1 B 3 C D C B 2 A 4 B and D

8 3 48 cm 4 20 1 52 cm 2 68 cm ca 52 An insect starts climbing a conical birthday hat of radius 5 cm at base It starts from point A a reaches point B taking spiral path on the hat Find out its displacement if height is 12 cm 12cm P B A 1 12 cm 2 8 cm 3 13 cm 4 25 cm Three particles P Q and R are situated at point A on the circular path of radius 10 m All three particles move along different paths and reach point B as shown in figure Then the ratio of distance traversed by particles P and R is QO A R 5 cm

2 What should be the deflection of tangent galvanometer so that the reading obtained through it has maximum accuracy 1 45 3 37 2 30 4 29 2

5 Newton s second law for finite size objects or a system of particles is Exactly same to Newton s second law for particles Based on Newton s second law and also on Newton s third law for particles Based only on Newton s third law for particles An extended form of Newton s second law for particles