Basic Physics Questions and Answers

Before the advent of ohmmeters even the analog ones unknown resistances Runk were measured using a Wheatstone bridge The unknown resistance is placed into the circuit at right as shown The values of R and R are extremely well known The resistance of Rvar is adjusted until the meter reads no current in the cross branch The value of Rvar is then read from a dial www Show that Runk can be found from Rukn R Ry R Runk ww R Rvar

21 consecutive nodes vibrate with different frequency phase and amplitude For visibility of diffraction pattern of waves of 21 ferra fer f pre light size of slit or obstacle should be TE ST 1 of any order 1 farfe 2 of order of wavelength 2 at an 3 very less as compared to wave length 3 143 144

One mole of a gas expands with temperature as V KT What is the work done when temperature changes by 30 C 1 10R 3 30R 2 20R 4 40R 28 a stan V KT 30 C fau and am 1 10R 3 30R 2 20R 4 40R

Example 7 A force F 2x1 newton acts in a region where a particle moves anticlockwise in a square loop of 2 m in x y plan as shown in Fig 4 36 Calculate the total amoun of work done Is this force a conservative force a a non conservative force

4 points It is raining vertically with a speed of 10 m s in still air A runner starts running with a speed of 10 m s in west direction What is the magnitude of velocity of rain as observed by

An aeroplane which together with its load has a mass M 9600kg is falling with an acceleration of a 5 m s If a part of the load equal to m kg be thrown out the aeroplane will begin to rise with an acceleration of a 5 m s Find the value of m A 6400 C 6600 B 6450 D 6700

A block of mass 2kg is resting on a frictionless plane It is struck by a jet releasing water a 1 kgs and at a speed 5ms Find initia acceleration of the block A 1 ms C 4m s 2 B zero D 2 5ms

AB is a wire of uniform resistance The galvanometer G shows no current when the length AC 40 cm and CB 60 cm as shown in figure The resistance R is equal to R A O 400 O 500 O 150 O 30 Q www 75 2 B

A rectangular loop PQRS 10 cm x 50 cm is placed in a plane perpendicular to uniform magnetic field Bo 0 5 T and pulled out of the field region with a constant velocity vo 2 m s At the instant shown in the figure QR is outside the field region The resistance per unit length of the wire is 192 m Vp Vs will be 1 Hy Bo 0 5 T x 10 cm S X X P X 2 11 y x x 50 cm X X R Q Vo 2 m s 3 v Ly 4 4 v

3 Electric field due to conducting parallel plates at any point near to a plate is E then what is the electric potential difference on moving a distance x parallel to the plates 1 Zero Pou Plate 3 Ex 2 11 2 2 Ex 4 Ex

3 A copper wire and a carbon wire has resistance of 20 ohm and 22 ohm respectively at 15 C At what temperature their resistance will be equal Temeperatre coeff of resistance for copper and carbon are respectively 428 x 10 5 C and 515 x 10 6 C at 15 C

73 180 When Eext 1 1 volt is applied in Daniel cell having electrodes of zinc an copper dipping in one molar solutions of their respective salts then O Electrons flow from Cu to Zn O Electrons flow from Zn to Cu O Zn dissolves at anode and Cu deposits at cathode No flow of electrons or current

passes successively over the two halves of a given distance with accelerations a and a 2 respectively Show that the final velocity is the same as if the whole distance is covered with a a a uniform acceleration 2 Sol In the first case Out s a First case s az v u 2a s v 2 2a s Adding Eqs i and ii we get In the second case u a a 2 Second case 2s Pra 29 a 28 V i ii or u a2 1 2 2 24 U V 0 s U 2 a 9 iii Example 3 23 constant acc displacemer time interva Sol i Displa iv Displac Displa

91 A projectile is thrown with some initial velocity at an angle a to the horizontal Its velocity when it is at the highest point is 2 5 2 times the velocity when it is at height half of the maximum height Find the angle of projection a with the horizontal a 30 POIDSM b 45 c 60 d 37 S 1 kg is projected with velocity 50 ms highest

3 4 In the potentiometer circuit shown the galvano shows no deflection for AD 35 cm The resistance of wire AB is 18 2 and its length is 50 cm Calculate the emf E of the cell A 292 20 V 1 10 V D B 2 14 V

In a potentiometer arrangement of a cell of emi cm length of wire Now when the cell is replaced by another cell the balance point shift to 60 cm The emf of the second cell will be 01V 03V 02V 04 V

3 ns If E E E E are the respective kinetic energies of electron deuteron proton and neutron having same De Broglie wavelength Select the correct order in which those values would increase a c E E E E E E4 E3 E h b d E E E E3 E E E E

A transformer having efficiency of 90 is working on 200 V and 3 kW power supply If the current in the secondary coil is 6 A the voltage across the secondary coil and the current in the primary coil respectively are AIPMT 2014 1 300 V 15 A 3 450 V 13 5 A 2 450 V 15 A 4 600 V 15 A voltage

line of a double ionised lithium atom Z 3 is 2 9 3 A 8 4 2 27 1 2 3 A wire of area of cross section 10 m is increased in length by 0 1 The tension produced is 1000 N The Young s modulus of wire is 1 1012 N m 2 10 1 N m 3 1010 N m2 4 10 N m 15 ton at and t A 1 2 3 2 2 9 3 7 8 4 2 27 10 60 1 af 1000 were 1 10 2 N m 3 1010 N m 2 10 N m 4 10 N m 2

ALLEN 10 Assume a bulb of efficiency 2 5 as a point source 10 HAT for 2 5 The peak values of electric field produced by the radiation coming from a 100 W bulb at a distance of 3 m 3 m is respectively 1 2 5 V m 3 4 08 V m 2 4 2 V m 4 3 6 V m If the potential energy of a gas molecule is 11 11 for 1 2 5 V 3 4 08 V m 100 farfa for at fefer 2 4 2 V m 4 3 6 V

1 2 5 V m 3 4 08 V m 2 4 2 V m 4 3 6 V 1 If the potential energy of a gas molecule is MN M and N being positive constants then the potential energy at equilibrium must be 1 Zero 2 M 4N 3 NM 4 4 MN 4 2 The charge q on a capacitor varies with voltage as shown in figure The area of the triangle AOB represents 11 12 3 4 08 V m 1 Um faff fe M N feff 4 3 6 V m er at fee 2 M 4N 3 NM 4 4 MN 4 frat me fange AAOBien 9

A capacitor a resistor and a 40 mH inductor are connected in series to anAC source of frequency 60Hz calculate the capacitance of the capacitor if the current is in phase with the voltage Also calculate the value of X and 1 R 2200 oooo V 300V 300V XV 110V 60Hz suce

ance r 26 Four identical cells of emf and internal resista are to be connected in series Suppose if one of the cell is connected wrongly then the equivalent emf and effective internal resistance of the combination is fa 2E and 4r c 2E and 2r b 4E and 4r d 4E and 2r y KCET 201

Which of O Order of a reaction cannot be zero O Molecularity is applicable to elementary as well as complex reaction O Order is applicable to elementary as well as complex reactions O For complex reaction order is given by the fastest step

5 A body is moving under the action of two forces Fi 21 5j F 31 4j Its velocity will become uniform under an additional third force F given by 1 51 2 si 3 5i 4 51 9 MAJOR ONLINE LEADER TEST SERIES JOINT PACKAGE COURSE OLTS Page 2 36 gan fars faff at we F 21 51F 31 4 staria fara a faftig am 1 si 2 si j 3 si 4 51 9j 09990MD610919007 Space for Rough Work dfere are NEET UG 2020 03092020 5

Value of inductance and capacitance is 0 1H and 200 F in a resonant circuit if value of inductance is changed to 100H at that resonatic condition than find the new value of capacitance 2 0 2 F 4 0 3 F 1 4 F 3 2 F

Topic Full Syllabus The two vectors have magnitudes 3 and 5 If angle between them is 60 then the dot product of two vectors will be 1 7 5 2 6 5 3 8 4 4 7 9 Two slits saperated by 4 mm are illuminated by light 1 2 360 a fanfare quem 1 7 5 2 6 5 3 8 4 4 ffef6000 4 7 9

B Fill in the blanks Maurya Lions Saffron Prosperity Rabindranath Tagore 1 The dark green colour in the national flag symbolises prosperity 2 Ashoka was a great king of Maurya dynasty 3 Our National Anthem Jana Gana Mana was composed by Rabindranath Tagor 4 Our National Emblem has four 5 The three colours in our National Flag are green white and dark

0 5 A Radio receiver receives a message at 300m band If the available inductance is 1 mH then calculate tequired capacitance locity of EM waves c 3 108 m s Ans 25 p

An L shaped object made of thin rods of uniform mass density is suspended with a string as shown in figure If AB BC and the angle made by AB with downward vertical is 0 then B 1 tan 0 tan A N 1 2 3 2 A 90 C N 2 tan 0 4 tan 0 1 2

In a reaction X Y product if concentration of X is increased to three times then rate increases by a factor of 3 and when the concentrations of both the reactants X and Y are tripled then rate increases by a factor of 9 The rate law for the reaction can be written as O Rate K X Y O Rate K X Y O Rate K X Y O Rate K X Y

t force 5 m s n b force o rest time 2 67 A simple Atwood machine composed of a single pulley and two masses m and m is on an elevator When m 44 7 kg and m 45 3 kg it takes 5 0 sec for mass m to descend exactly one meter from rest relative to the elevator What is the elevator s up motion Ans 2 m s upwards

what ntal thes the 3 72 In a vertical circle AB is the horizontal diameter Let AD and AE are two cords of the circle which subtend the angles 0 and 20 at the centre of the circle respectively If a particle slides along the two cords from A to D and A to E and the ratio of the time durations it take to travel the distances AD and AE is 1 n then prove that n 1 cose 1

4 The reading of voltmeter and ammeter in the following figure will respectively be X 42 a 0 and 2A c 2V and 2A m X 492 90V ww R 45 Q b 2A and OV d OV and 0A circuit the values of current flowing in

If m 20 kg m 30 kg m is on smooth surface Surface between m and m has 0 5 and 0 Find the acceleration of m and m for the following figures when for figure a i F 160 N ii F 175 N figure b F 160 N m m F m m F

13 An electron moves in a circular orbit with a uniform speed v It produces a magnetic field B at the centre of the circle The radius of the circle is proportional to B B a V b B c VB d V V A conducting rod of length L and mass m is moving down a c 18 A SU

6 29 The orbital period of revolution of a planet round the Sun is T Suppose we make a model of Solar system scaled down in the ratio n but of materials of the same mean density as the actual material of planet and the Sun has The new orbital period is A nTo C n T B n To D To

60 Hz 2 0 H Figure 13 2 2 0 H What is the total reactance in Figure 13 2 37 70 754 00 377 00 3 770 Q

A battery applies 45 volts to a circuit while an ammeter reads 10 mA Later the ammeter reading drops to 7 mA Assuming the resistance has not changed the voltage must hav increased to 58 5 volts decreased to 31 5 volts decreased 30 from its old value both B and C are correct stayed the same

4 X Y Z Temperature of 100 gm water is changed from 3 0 C to 3 C in this process heat supplied to water will be specified heat of water 1 cal g C 1 1 equal to 300 cal 2 greater than 300 cal 3 less than 300 cal 4 data is insufficient 4 X Y Z 100 gm0 C 3 C ufafda fam f 1 cal g 1 300 calare 2 300 cal fur 3 300 cal 4

1 25 A 2 11 A 3 2 2 A 4 1 1 A A screen is placed 50 cm from a single slit 7 which is illuminated 6000 A light If distance between first and third minima in the diffraction pattern is 3 00 mm then width of slit 1 0 1 mm 3 0 3 mm 2 0 2 mm 4 0 4 mm 1 25 A 2 11 A Vi hauffa fic 6000 AT 3 2 2 A 4 1 1 A 50 cm a minima 3 00 mm at fete fr 1 0 1 mm 3 0 3 mm af faada 2 0 2 mm 4 0 4 mm fa

Level 2 Only One Correct Option 1 A charged particle P leaves the origin with speed v v at some inclination with the x axis There is a uniform magnetic field B along the x axis P strikes a fixed target T on the x axis for a minimum value of B Bo P will also strike Tif a B 2B v2vo c Both are correct Two infinitely long conductors carrying equal currents are honed as shown The b B 2Bo v v0 d Both are wrong An ionized gas cont initially at rest If electric field alon along the z dire a positive ions y directic b all ions de c all ions c d positive toward 4 Two pr point w exists stren of w

SS ic he 35 a und b speeds up bet c speeds up in a dee d slows down within a dee and speeds up between dees 36 A circular current loop of magnetic moment M is in an arbitrary orientation in an external magnetic field B The work done to rotate the loop by 30 about an axis perpendicular to its plane is MB a MB 2 b 3 of the magnetic field MB 2 d zero

23 If a rolling body s angular momentum changes by 20 Sl units in 3 seconds by a constant torque Then find the torque on the body 2019 a 20 3 Sl units b 100 3 Sl units c d 5 S1 units 20 S1 units Sl

A capacitor of capacitance 5 F is connected as shown in the figure The internal resistance of the cell is 0 5 Q2 The amount of charge on the capacitor plate is www 1 0 192 5 F 46 2 5V ww 192 292 www

powe 4 depends on source voltage Work done in moving a positive charge on an 42 equipotential surface is 1 finite positive but not zero 2 finite negative but not zero 3 zero 4 infinite 414141414 4 va vida a fan of 1 H 2 3 4 3

3 H PO 4 H PO 5 The rate constant for the reaction 2N O 4NO O is 3 10 sec If the rate is 2 40 x 10 mol litre s sec Then the concentration of N O in mol litre is 1 1 4 2 1 2 3 0 8 4 0 4 55 3 H PO 2N O5 10 sec af N 4 H PO 4NO 0 3ffen anat fredis 3 x 2 40 x 10 mol litre sec mol litre 1 1 4 2 1 2 3 0 8 4 0 4

each diagram shown in the figure a to f Question Find the direction of force on a negative charge for each diagram shown in the figure a to f where green is the velocity of the charge and B blue is the direction of the magnetic field a e B 9 B B b d f B B

4 24 A series of N identical balls are at rest on a smooth horizontal surface The number 1 ball moves with velocity u towards the ball number 2 which in turn collides with the ball number 3 and so on Find the speed of Nth ball if the coefficient of restitution for each impact is e Ans u 1 e N 1 2N 1

The figure below shows a man holding a box of mass 15 kg Determine the moment produced by the weight of the box about point E Given that d1 0 9 m d2 0 4 m and d3 1 5 m A d2 m C di m di m m E W d3 m D B