Basic Physics Questions and Answers

State whether the following statements are true T or false F Correct the false statements 1 A simple machine makes work easier by providing energy on its own T 2 Class II lever works like a force multiplier T 3 The smaller the lead of a screw the higher is the mechanical advantage T 4 A movable pulley reduces the effort used to pull the load T 5 The wheel and axle must move alternately to form a simple machine F 6 The efficiency of every machine used by us is always equal to 100 F

3 A system consists of two identical particles One particle is at rest and the other particle has an acceleratio a The centre of mass of the system has an acceleration of Uchaf FORUT 1 2a 2 a 3 a a 4 he a of

2 18 The dielectric to be used in a parallel plate capacitor has a dielectric constant of 3 6 and a dielectric strength of 1 60 x 107V m The capacitor is to have a capacitance of 1 25 10 F and must be able to withstand a maximum potential difference of 5500V What is the minimum area the plates of the capacitor may have Ans 0 0135m

If the magnetic field of earth at any point on the magnetic equator is 0 4 x 10 T then the value o magnetic field at the magnetic pole of the earth i approximately 10 4 104 T 2 0 2 x 10 T 3 0 8 x 10 4 T 4 0 3 x 10 T St unit of intensity of magnetisation is

A particle of mass 2 kg travels along a straight line with velocity v a x where a is a constant The work done by net force during the displacement of particle from x 0 to x 4 m is 1 a 2 2a 3 4a 4 12 0

2 P and Q 3 P and Q 4 Q and Q Assume that each iron atom has a permanent magnetic moment equal to 4 Bohr magnetons 1 Bohr magneton 9 27 x 10 24 Am The density of atoms in iron is 8 52 x 1028 atoms m The maximum intensity of magnetization in a long cylinder of iron is 1 0 58 x 106 A m 2 2 58 x 106 A m 3 1 16 x 106 A m 4 3 16 x 106 A m wer 8 Pusa Road New Delhi 110005 Ph 011 47623456

of mass 100 g is dropped from a height of 1 m It loses 10 of its energy every time when it bounces off the floor After 3 bounces it car reach the half way to maximum height its kinetic energy upto two decimal points would be take g 10 m s 3 20 1 0 35 J 0 36 J 0 70 J 40 73 J 2 3 9 To D 1 0 09 81 1 210 0 TO 03 0 81 0 72 8 10 72

A train moving at uniform 90 km h is approaching a flag station whose platform is 500 m long Station master is standing a the centre of the platform Train start blowing whistle when engine is 1 km awa from near end of the platform and continue blowing whistle till engine crosses of th platform without stopping If the speed c the sound is assumed to be 300 m s the the duration for which station master Hea the whistle is 1 55 80 sec 56 67 sec 60 00 sec 60 30 sec 3 4 25m 5 Vs 2300m

A beam having photon of energy 480 k eV is incident on a foil of aluminum If the photon is scattered at 45 then calculate the energy of the recoil electron a 2 56 10 4 J b 1 65 10 14 J c 3 28x10 4 J d 4 12 10 4 J

20 g of ice at 20 C is dropped into a calorimeter containing 20 g water at 10 C The specific heat of water is twice that of ice The amount of water contained in the calorimeter when equilibrium is reached is 1 20 g 2 10 g

90 Design a counter which counts from 0 to 15 using positive edge clock pulse Draw the sequential circuit using CIRCUIT VERSE tool How we can say that J K flip flop is a universal flip flop Explain

The possible value of magnetic susceptibility of a diamagnetic material can be 1 2 45 3 0 5 2 0 75 4 1 67 tion factor of tangent galvanomete

A negative charge is coming towards the observer The direction of the magnetic field produced by it wil be as seen by observer feel GRI GI Y 1 Clockwise 3 In the direction of motion of charge 1 fa 3 fam R34 2 Anti clockwise 4 In the direction opposite to the motion charge 2 4 ffaria farm

7 Amplitude of electric field in an electromagnetic wave of intensity 1 475 W m is nearly 1 49 67 N C 2 33 33 N C 3 66 66 N C 4 53 8 N C shown in the fiqure masses

Two blocks of mass 2 kg and 3kg having coefficient of static friction 0 3 and 0 4 respectively are joined by an ideal spring of constant 100 N m and kept on level ground What can be a possible extension in the spring so that both the blocks are in equilibrium Take g 10 m s 03 cm 6 cm 9 cm 15 cm

Here a is the angle formed by the helical line of groove with the horizontal plane A component of the acceleration of the body is responsible for change in direction other for the change in speed i e centripetal acceleration tangential acceleration The tangential acceleration have two components one along the circle one in vertical direction The value of tangential acceleration at can be found by mentally developing the surface of the cylinder with the helical groove into a plane In this case the groove will become an inclined plane nh 2 Rn Distance travelled by the object when it completes one revolution along the groove is

3 3 4 4 39 A light has amplitude A after passing through the polariser Angle between analyser and polariser being 60 Light transmitted by analyser has amplitude 1 A 2 3 3A 2 2 1 2 4 A 2

Charges 3Q Q are fixed as shown in diagram Then which of the following graph correctly represent the variation of electric field intensity along the line joining the two charges A B C D 3Q 3Q 3Q 3Q 3Q Q Q

5 Sound travels at a speed of 1450 ms through water A submarine detects object around it by sending sound waves and detecting echo reflected sound heard afte 4 seconds Then the object must be at distance of 1 1 450 km 2 2 900 km 3 4 350 km 4 5 800 km Ad 1450 2 M 2900km

In YDSE d 1mm 6000 and D 1m The minimum distance between two points on screen having 75 intensity of the maximum intensity will be 1 0 50 mm 3 0 30 mm 2 0 40 mm 4 0 20 mm

38 Consider two circuits 7 hp XE L i A in which N identical bulbs are connected in series across a battery of emf E ii B in which N bulbs identical to those in A are connected in parallel across similar battery of emf E PA Power dissipating in each bulb in A PB Power dissipating in each bulb in B PAT Total power delivered by battery in circuit A PBT Total power delivered by battery in circuit B Choose the correct option PA N PBT PBT N PA 1 2 3 4 PBT N PAT PB N PA PA Ex hr 2 hR Ca Ehr

A block placed on x y plane at origin and is pulled by two forces F F where F is towards 3 4 m and F towards 4 3 m F is of magnitude 9 N and F is of magnitude 12 N O F can be expressed as 31 41 N IN F2 can be expressed as 12 41 31 L N 5 F F can be expressed as 15Ni component of F F 2 along y axis is zero 1

Width of a slab is 6 cm whose If its 2 rear surface is silvered and object is placed at a distance 28 cm from the front face Calculate the final position of the image from the silvered surface 2 10 3 60 1 30 4 45

When unpolarised light beam is incident from air onto glass n 1 5 at the polarising angle 1 Reflected beam is polarised 100 percent refracted beams are 2 Reflected and partially polarised 3 The reason for 1 is that almost all the light is reflected 4 All of the above

Cord is wrapped around a wheel in vertical plane and it can rotate about horizontal axis At end of string a block of weight mg is attached System is released from rest Find square angular frequency when block descends by height h 3 1 2mgh I MR mg mg T ma TR la a Ra mg a V R Ia R ma mg m I 2 R 2mgh m I R OR 2 mgh I 2mR 2mgh I 2mR 4 mgh I MR JUTE Jiable

Q61 The reading of the ammeter as per figure shown is 292 1 A 2 A 3 A 4 2 A 1 252 ww 2V H 252 ww 252 www A 2 72 From NCERT 3 4

Q65 A current of 2 A flows in a system of conductors as shown The potential difference VA VB will be 2A D 252 352 1 2 V 2 1 V 3 1 V 4 2 V B 30 292 www C 2 2A 292 352 ww 1 Subtopic Kirchoff s Voltage Law 3 A B 352 202 4

Two coherent point sources S and S are separated by a small distance d as shown The fringes obtained on the screen will be 1 points vous d S S D Screen 2 straight lines

A block of mass 10 kg is placed on a rough inclined plane of nclination 370 tan 37 3 4 The coefficient of friction between block and surface is 0 4 A horizontal force F 50 N is applied on the block then g 10 m s F TITI 370 10kg u 0 4 acceleration of block is zero acceleration of block is 2 4 m s along the inclined plan frictional force between block and surface is 44 N frictional force between block and surface is 20 N

A bird is flying towards north with a velcoity 40 km hr and a train is moving with velocity 40 km h towards east What is the velocity of the bird noted by a man in the train 33 40 km hr fafir 40 km hr Griffe au fondal frente fa 1 40 2 km hr north east 3 40 2 km hr north west 2 40 2 km hr south east 4 40 2 km hr south west

5 A particle moves along X axis from x 0 to x 1 m under the influence of a force given by F 3x 2x 10 Work done in the process is 1 4 J 2 4 J 3 8 J

0 2 0 1 1 2 M 3 4 If in the system shown the initial acceleration of wedge of mass 5M is then value of x is pulley are 17 ideal and the chords are inextensible and there is no frictional any where uft zuf T Agru 5M GHH x 1 far gngef v zeeft at the adu bufera 1 17 5M t 2M Initially system is in equilibrium such that extention in each spring is same and spring constant of each 10n spring is k 100 N m Acceleration of block just after 1st and 3rd spring are burnt simultaneously is

1 Three 60 W 120 V light bulbs are connected across a 120 V supply If resistance of bulb does not change with temperature then find out power delivered to bulb A 120 V 1 20 W 3 80 W A BIO Cil 2 W 40 3 4 80 W

Magnification of a compound microscope is 30 Focal length of eye piece is 5 cm and the image is formed at least distance of distinct vision Find the magnification of objective 1 7 2 5 3 6 4 8

Question No 8 Ring A can slide on a smooth horizontal rod and block B can move vertically Both are attached by an inextensible string At a certain instant velocity of ring is v and of block is v2 At that instant ring is at a horizontal distance b from pulley as shown Then V V cose V1 V Cose V sin 0 h2 A Ongular velocity of the ring with respect to an observer on the pulley is V a2 a cose where a2 and a represent the accelerations of block and ring respectively at that instant 0 wwwwwwww B a Iv k Save

8 A 400 kg boat is 6m long It is floating in still water and is at rest A person of mass 80 kg moves from one end of the boat to the other Displacement of the boat relative to water is 1 1m in a direction opposite to the displacement of person 2 0 5m in a direction opposite to the displacement of person 3 1 5m in a direction opposite to the displacement of person 4 1 5m in the direction of displacement of person

Q22 The sun appears two minutes before the actual sunrise due to atmospheric refraction How does sunlight travel from space to atmosphere b to Sun Sun Atmosphere Atmosphere d Sun Sun Atmosphere

ns pl For given R L C circuit find out the peak current and resonance frequency 100mH 100 F wwwww 1 2A 10 Hz 2 Z R x x 120 10 100 15092 Io V 30 Z 150 1 VLC 2 100 ho 0 2A 1 10 x104 100 2x 10 30 sin 100t 2 0 2A 5Hz 5Hz 1 10 5 12002 www 2nf 3 2A 5Hz UN 4 0 2A 10 Hz

Q58 The potential difference between points A and B of the adjoining figure is A 55 592 D www 1 V 2 V 3 V 4 2 V 1 592 552 ww 2V 592 www 592 ww 2 50 B C 3 4

A simple penauium of lengin L IS constructed from a point object of mass m suspended by a massless string attached to a fixed pivot point A small peg is placed a distance 2L 3 directly below the fixed pivot point so that the pendulum would swing as shown in the figure below The mass is displaced 5 degrees from the vertical and released How long does it take to return to its starting position L fixed pivot point small peg

Cost of coal is 5 per kg and can produce energy of 20 MJ kg If a power station uses coal to produce electricity with 25 efficiency then the cost of coa for producing 1 unit 1 kw h of electricity in kw h R 3 6x166J 0 9 2 3 6 3 9 0 4 36 0 20x106 5 31 x5 3 6 S

Aakash Rank Booster Test Series for NEET 2020 11 An unpolarised beam of light is made to incident on an arrangement of four polarising sheets arranged in such a way that the characteristic direction of each polarising sheet makes an angle of 45 with that of preceding sheet What fraction of incident unpolarised light will be transmitted finally 1 3 ww 1 1 16

at will be process electron atom of r s model o be true f electron 4 Only a b and d are correct 36 In the circuit given below neglecting base emitter voltage VB find the collector current Vcc 8V 500 k 1 0 78 MA 3 1 28 mA B 80 2 0 96 MA 4 2 20 mA

12 In YDSE when a thin transparent sheet of thickness t and refractive index u 1 5 is placed just in front of upper slit the central bright fringe shifts to nth bright fringe Then n is Wavelength of light in air 3 t 22 2 2 4 2 2t 22 t

If time taken by a simple pendulum for 10 oscillations is measured as 50 s with stop watch of least count as 1 s Maximum permissible percentage error in the time period of oscillation is Question 2 Acceleration a of a particle moving in a straight line varies with its velocity v in m s as a 2 2 v m s Find the maximum possible speed of the particle assuming at t 0 particle was at rest

The aperature of telescope is 5 cm distance between moon and earth is 4 10 km Find the minimum separation between two objects on the surface of moon which can be resolved 5000 1 1 21 km 3 3 21 km 2 5 km 4 4 88 km

R with a coil of inductance L in series with them The power source could be an AC or a constant voltage DC source When AC source is applied then XL Xc R L wwwo C R If an AC source Cocoswt is applied across the input terminal then Question Type Multiple Correct Type 250 1 The peak value of current through AC source will be R So 2 The peak value of current through AC source will be 2R So 3 The peak current across capacitor will be R

Zero Marks A stone is dropped from a certain height The ratio of speeds averaged over total distance and total time of fall is x 3 value of x is Backspace

For a hydrogen atom when electron jump from n 2 to n 1 then wave length of radiation emitted found to be Then for which transition of electron of a He atom the wavelength of radiation emitted will be equal to 1 n 3 to n 2 2 n 4 to n 2 3 n 4 to n 3 4 n 8 to n 4

A circular loop of radius R is bent along a diameter L and given a shape as shown in figure One of the semi circles KNM lies in the x z plane and the other one KLM in the y z plane with their centres at origin Current I is flowing through each of the semi circles as shown in figure A particle of charge q is released at the origin with K qVoHol k I 4R M N Z a velocity V V Find the instantaneous force F on the particle Assume that space is gravity free a b X qVoI 2j 5R