Physics Questions

5 A telescope has an objective lens of focal length 150 cm and an eyepiece of focal length 5 cm If a 50 m tall tower at a distance of 10 km is observed through this telescope in nor mal setting the angle formed by the image of the tower is 0 Then is close to a 1 c 3 b 15 d 9

In the given A C circuit the instantaneous current through inductor and capacitor are 0 8 A and 0 4 A respectively The instantaneous current through the resistor is 1 1 2 A 2 0 6 a wwwww R 3 0 4 A 4 V0 8 A 000000 Htc

2b A researcher is trying to use an old Q band microwave spectrometer to view at least one rotational energy transition for 79Br 9F g The rotational constant for this molecule Is B 0 357cm If the frequency range of the instrument is 36 0 50 0 GHz 1GHz 1x100 Hz which rotational transition will be observed Write the quantum numbers associated with the transition below and mark it with an arrow on the energy level diagram you drew in part a

Two thin lens have a combined power of 10 D in contact When separated by 20 cm their equivalent power is 6 25 D Find their individual powers in dioptres A B C D 3 5 and 6 5 5 and 5 7 5 and 2 5 9 and 1 Correct Answer

Give an example of appliances at home that is connected using a series connection Draw the circuit in a series connection

O APPARENT WEIGHT Because of upward force acting on a body immersed in a fluid either wholly or partially there occurs an apparent loss in weight of the body The net weight of an object immersed in a fluid is called apparent weight W W Th W is the true weight of the body App Decrease in weight W WA App Note i Using Archimedes s principle we can determine relative density R D of a body as R D Th Weight of the fluid displaced density of body wt of body density of pure water at 4 C wt of equal volume of water wt of body thrust due to water wt of body loss of wt in water wt of body in air wt in air wt in water ii If a body is weighed in air WA in water W and in a liquid W loss of weight in oil WA W loss of weight in water W W then specific gravity of oil

2 5 Having gone through a plank of thickness h a bull changed its velocity vo Find the time of motion of the bullet the plank assuming the resistance force to be proportional the square of the velocity Ans h vo v vorloge 1

from them Object e Mirror c Image ages Name of the mirror a b d f 3 2 Which mirror among the above can be used to form the image

2 A mountain climber is sliding down a vertical rope Her total mass including equipment is 65 kg By adjusting frictional force of the rope she controls the force that the rope exerts on her For a 2 0 s interval this force T is shown as a function of time t in the given graph What is change in her speed in this interval Assume acceleration of free fall to be 10 m s and neglect air resistance a 5 m s c 15 m s b 10 m s d 20 m s 3 A boy of mass 50 kg is standing at one end of a 90 m long boat of mass 650 325 ATIN 0 2 tls 2 0

Consider an apple of mass m and that falls off a tree A common model for its speed v t after t seconds that takes air resistance into account is mg v t m 1 el c m C Here g is the acceleration due to gravity and c is some positive constant a Calculate lim v t Your answer may involve the constants c g and m 1 00 b For fixed t calculate lim v t Your answer may involve the constants c g and t m 400

In the figure shown M 7 kg is placed on horizontal surface and m 2 kg is attached with a spring of k 700 N m which is initially in natural length and string is just taut Now the m is released from rest During subsequent motion Eeeeee The block of mass M will not leave the contact with horizontal surface The block of mass M will leave the contact Minimum normal force on M by horizontal is 3g Velocity of block of mass m when heavier block just leaves the 1 contact is m s

This question has multiple correct options A B C D the total kinetic energy of the system is always conserved Correct Answer the kinetic energy of the system before collision is equal to the kinetic energy of the system after collision the linear momentum of the system is conserved Correct Answer Correct Answer the mechanical energy of the system before collision is equal to the mechanical energy of the system after collision

99 A body of mass 1kg is moving in the upwar direction with an acceleration of 2m s Calculat the work done by tension in first second at t C u 0 1 10 Joule 3 24 Joule AT 1kg 2m s 2 12 Joule 1 20

A T shaped rod is placed in xy plane as shown in the figure If the rod is uniform and both parts are of equal length L and mass m then distance of centre of mass of the system from origin will be Ignore thickness of the rod Ay L 45 12 2 3 4 2 Pama H 2 4 4 3L 4 X

twice the diameter twice the tension and twice the density of string B The overtone of A that will be in unison with fundamental frequency of Bis 1 4th 23rd 3 1st 4 2nd 39 A uniform rope having mass hangs vertically from rigid support A transverse wave pulse is produced at the lower end The frequency of wave pulse varies with x from the lower ends as ww 2 Ja Le T R 2 1 JB 4 Ja 1 40 The first overtone of an open organ pipe has frequency f The second overtone of a closed organ pipe of the same length will have frequency neglect end corrections 5f 2 5f 4 v Jgn J v gn 3f 2 3f 4 41 The equation of stationary wave is y 10 cos TX sin 100 where x is in cm and 10 tis in s The wave is formed on a string of length 40 cm An antinode will be located at from the following options F 2 4 He 2 x 25 cm 3 x 20 cm 4 x 12 5 cm 42 A motor cycle starts from rest and accelerates along straight path with an acceleration of 4 m s away from a stationary electric siren How far the motor cycle must have travelled when the rider hears the frequency of siren at 90 of its value when motor cycle was at rest speed of sound 330 m s 1 136 m 2 156 m 3 76 m 4 196 m To 43 The equation of a travelling wave on 2 string moving in positive x direction is given by y Asin ot kx It is reflected from a rigid boundary at x 0 The equation of rellected wave is y CE 1 Asin of kx 2 Asin cot kx 3 Asin of kx 4 Acos ot kx 44 The velocity time v t graph of a particle executing S H M is shown below The acceleration of the 5 3 particle at t s will be V 5 cm s 3 cm s 1 2 3 5 3 2 5K 3 2 5 0 cm s 2 av v r 4 F v cm s cm s 3 76 6 J 4 Zero 45 Which of the following quantity is always negative in SHM2 Symbols have usual meanings Fr cos 90 O 9 Costo 20 t s vtu 330 330 1 5 tamax 1

Examine the table Items A B C D E TI F Colour in acid No colour Light pink Black Yellow Red White Colour in alkali Pink Light yellow Black Red Blue White 1 Which of the above items can be used as indicators 2 Name the items A and E 3 Name two natural things which can be used as indicators

An a particle of mass m suffers one dimensional elastic collision with a nucleus at rest of unknown mass It is scattered directly backwards losing 64 of its initial kinetic energy The mass of the nucleus is 2019 Main 12 Jan II

In the vacuum tube experiment with perfora ted anode what will happen to the emitted e lectrons after hitting the phosphor material How the electrical neutrality is maintained Also in anode how the electrical neutrality is maintained Sir Can you please clear my dou

Calculate the radius r of a circular spot of liquid after 25 seconds The droplet volume is 5 5 mL 3 The liquid has density 970 kg m and dynamic viscosity 0 106 Pa s The droplet has an initial height which is larger than the capillary length of the liquid The acceleration due to gravity is 9 81 m s 2 Give your answer in mm show your working

A radar has a power of 1 kW and is operating at a frequency of 10 GHz It is located on a mountain top of height 500 m The maximum distance in km upto which it can detect ob ject located on the surface of the earth Radius of earth 6 4 106 m is

41 Two different sound sources Sand S have freqencies in the ratio 1 2 Source S is approaching towards observer and S receding from same observer Speeds of both S and S are V each and speed of sound air is 330 m s If no beats are heard by the observer then the value of V is 2 1 50 m s 2 75 m s 3 110 m s 4 125m s

The binding energy per nucleon of Li and He nuclei are 5 60meV and 7 06meV respectively In the nuclear reaction Li H He He Q the value of energy Q released is a 19 6MeV b 2 4MeV c 8 4MeV d 17 3MeV

A prism of a certain angle deviates the red and blue rays by 8 and 12 respectively Another prism of the same angle deviates the red and blue rays by 10 and 14 respectively The prisms are small angled and made of different materials The dispersive powers of the materials of the prisms are in the ratio A B 5 6 9 11

between their centripetal acceleration is 1 R r 2 r R 3 R 4 A particle covers equal distance around a circular 14 path in equal intervals of time Which of the following quantities connected with the motion of the particle remains constant with time 1 Displacement 2 Velocity 3 Speed 4 Acceleration 4 R Radius of the curved road on national highway in ETIT 1 R T fed ft 1 farsang 2 3 4 FRUT 2 r R 3 R 4 r R er fer

small distance d as shown The fringes obtained on the screen will be tous S S d B A points C D straight lines semi circles Screen

4 9 A charge of 1 coul is placed at one end of a non conducting rod of length 0 6m the rod is rotated in a vertical plane about a horizontal axis passing through the other end of the rod with angular frequency 104 T radian sec Find the magnetic field at a point on the axis of rotation at a distance of 0 8 from the centre of the path Now half of the charge is removed from one end and placed on the other end The rod is rotated in a vertical plane about horizontal axis passing through the mid point of the rod with the same angular frequency Calculate the magnetic field at a point on the axis at a distance of 0 4m form the centre of the rod

jective Questions rce A high speed car and an innocent insect have a head on collision The the poor insect over the windshield Is the corresponding force that the insect exerts against the windshield greater less or the same Is the retardation of the car greater than less than or the same as that of the insect fixed and of balance B is attached

A transverse wave is represented by the 2 equation y yo sin value of is the maximum particle velocity equal to two times the wave velocity Your Answer 2 A B C 3 vt x For what 2 Correct Answer

Diffraction pattern is obtained using red light What will happen if it is replaced by violet light Bands will get spaced apart Bands will remain fixed at same place Intensity pattern on screen will become 100 times Bands will come closer on screen

1 Centre of gravity C G of a body is the point at which the weight of the body acts 2 Centre of mass coincides with the centre of gravity if the earth is assumed to have infinitely large radius 3 To evaluate the gravitational field intensity due to any body at an external point the entire mass of the body can be considered to be concentrated at its CG 4 The radius of gyration of any body rotating about an axis is the length of the perpendicular dropped from the C G of the body to the axis Which one of the following pairs of statements is correct a 4 and 1 b 1 and 2 c 2 and 3 d 3 and 4 10101

k Solvelancer Test Which is the correct statement for the following structures Solvelancer Test CH T CH CH CH CHO I H C CH CHO Butanal 2 Methyl butanal a i and ii chain isomers b i and iii chain isomers c ii and iii position isomers d All are position isomers a b C d ii CH C CH CH 2 Butanone SolveLancer Test Which of the statement is correct for the given s t sraph 1 From 0 to t velocity is in negative direction II From 0 to t velocity is in negative direction III acceleration is negative throughout the motion 0 IV direction of velocity remains constantlSolvel ancer Testl t

ying straight i A rod of erpendicular city v then field variable with time as B Bot induced in the ring if the magnetic field is perpendicular to plane of loop is 1 mor 2 nar 3 2 4 n r The value of self inductance of a small circular col of radius r and number of turns n is 1 n r 2 Hon 2 4 Hon rr 4 wo colls A and Bha respectively are placed ne a current of 3A in A 104 Wb and with mutual inductance is 1 4 x 105 H 3 2 10 5 H 19 The primary ar have 60 and magnetic flus Hon r 3 14 n the circuit shown in the following figure E 10V R 292 R 392 R 692 and L 5H The current i just after pressing the switch S is wwwwwww R YR by do voltage ac Po are in 1 120 22 20 A tra lam A

A diverging lens of focal length 10 cm is placed 10 cm in front of a plane mirror as shown in the figure Light from a very far away source falls on the lens The final image is at a distance A B C D 20 cm behind the mirror 7 5 cm in front of the mirror 7 5 cm behind the mirror 2 5 cm in front of the mirror Correct Answer

You observe a star in another galaxy You compare its brightness with another star with the same pulsation period in your own galaxy with a known distance of d 1x10 4 light year the star in the other galaxy is 10 9 times fainter How far away is the other galaxy Express in light years

3 In the figure shown find work done by tension in string on 3 kg block in first two secon beginning of motion The system is set free at t 0 g 10 m s Assume pulley and string i A 96 Joule 2kg 3kg co Joule D 96 Joule

20 A bob of mass m is suspended by a light string of 20 length L It is imparted a horizontal velocity v at the lowest point A such that it completes a semicircular trajectory in the vertical plane with the string becoming slack only on reaching the topmost point C Match the column I with column II Am D Column I A Velocity at point V is B Velocity at point B is C Velocity at point C is Ration of kinitic energy at B and C is 1 A p B q C s D r 2 A q B C p D s 3 A B s C 4 D p 4 A s B p C r D q HB Columa II p 3 9 VBL r 5gr 3gL m HR fani mert a Las V I TOEISHUB Dredd HOT Y TINH Vo na mtu ana u organi rasan arafen if it Bao meet thu fing CT Thal GTHL KHI a fami A V B B finant C Cfn Am NI 48 Bargura 1 A p B C s D r 2 A q B C p D s 3 A B C q D p 4 A s B p C D q FII p 3 9 BL r 5gL s 3gL

4 81 A spring of free length 15 cm is connected to the two masses as shown in the figure 4 149 and compressed 5 cm The system is released on a smooth horizontal surface Find the speed of each block when the spring is again at its fre length The force constant for spring is 2100 Nm 2 kg 3 kg 1 k Hrrrrrrrrrrrrr Ans 1 575 m s 1 05 m s Figure 4 149 2

12 A block of mass m is moving with a constant 12 acceleration a on a rough horizontal plane If the coefficient of friction between block and the ground is u then the power delivered by external agent at time t is 1 mat 3 um a ug gt 2 umg at 4 m a ug at yra fa fa in gutes at et af H eft 1 mat 3 m a ug gt 2 umg at 4 m a g at

3 Zero 4 28 In the given figure there is current carrying straight wire of infinite length having current i A rod of length is coplanar with the wire and perpendicular to it If the rod moves with constant velocity v then the induced emf in the rod Tax Hoi vin a t MO viln 2 a a 2T

to q at th on Example 1 6 Consider three charges 9 92 93 vertices of an equilateral triangle of side 1 What is the force charge Q with the same sign as q placed at the centroid of the triangle as shown in Fig 1 9 3kQq 1 ezt 3k69 22 A 9 9 F E3 1 120 F2 z A

A stone is tied to a string of length and is whirled in a vertical circle with the other end of the string as the centre At a certain instant of time the stone is at its lowest position and has a speed u The magnitude of the change in velocity as it reaches a position where the string is horizontal g being ac celeration due to gravity is 1 u gl 2 u u 2gl 8 3 2gl bn leegi 4 2 u ge

An ideal monoatomic gas is enclosed in a vertical cylinde r An ideal monoatomic gas is enclosed in a vertical cylinder of area of cross section A and length I under massless frictionless piston connected to spring of spring constant K Atmospheric pressure is such that in absence of gas under the piston in equilibrium piston it just touches the bottom of the cylinder and spring is in stretched configuration Initially volume occupied by gas is 3rd of the volume of cylinder and the spring is relaxed Q amount of heat is supplied to gas slowly to move piston to the upper edge If Q 2x K 9 find 7 through the motion of the piston spring is in stretched configuration eeeeeee

Since direction of induced current is given in dia Therefor e magentic field produced according to the induced curre nt is vertically downward right hand thumb rule So the direction of magentic field should be vertically upward 19 For given arrangement in horizontal plane the possible direction of magnetic field 1 towards right 2 towards left 3 vertically upward 4 vertically downward Induced current mim because in motion 16 Eweley has

9 An air column in a tube 32 cm long closed at one end is in resonance with a tuning fork The air column in another tube open at both ends of length 66 cm is in resonance with another tuning fork When these two tuning forks are sounded together they produce 8 beats per second Then the frequencies of the two tuning forks are Consider fundamental frequencies only E 2013 1 250 Hz 258 Hz 3 264 Hz 256 Hz 2 240 Hz 248 Hz 4 280 Hz 272 Hz

41 A block of mass 20 kg is acted upon by a force F 30 N at an angle 53 with the horizontal in downward direction as shown in diagram The coefficient of friction between the block and the horizontal surface is 0 2 The friction force acting on the block by the ground is g 10 m s 1 40 0 N 3 18 0 N F 53 20 Kg TE 2 30 0 N 4 44 8 N

3 27 ms 4 36 ms 1 32 A ball is dropped from the top of a building The ball takes 0 5 sec to fall past the 3 m height of a window some distance from the top of the building If the speed of the ball at the top and the bottom of the windou are v and v respectively then g 9 8 m s 2 V VB 4 9 m s 1 V VB 12 m s 3 V V 1 m s 4 VT 1 m s

39 In the given diagram two particle A B having same charge mass respectively m m are moving in a magnetic field B with speed vand V then 1 MAY Me Va 2 MAVA My VB 3 m me and VA VB 4 m mg and VA VB He ALLEN 29 and fax 27 vero cha B VYB 1 MA VA M a 2 m vmeye 3 mm 12 AVB 4 m m 1 V VB

33 An object dropped from the top of a tower covers in the last second seven times the distance it covered in the first second Find the time of flight 1 2 s 2 3 s 3 4 s 4 5 s

In YDSE an electron beam is used to obtain interference pattern If the speed of the electron decreases then Distance between consecutive fringes decrease Distance between consecutive fringes increases Distance between consecutive fringes remains same More information is required

D A car going at 22 metres per second passes a motorcycle at rest As it passes the motorcycle starts up accelerating at 3 2 metres per second squared If the motorcycle can keep up that acceleration how long will it take for it to catch the car a 12 s c 20 s b 14 s d 18 s