Physics Questions

19 An infinitely long wire is kept along z axis from z to z having uniform linear charge 10 density nc m The electric field at point 6 cm 8 cm 10 cm will be nc 1 120i 160j 200k V m 3 160i 120j v m K X 2 200k V m 4 120i 160j V m Ans A

An irregular closed loop carrying a current has a shape such that the entire loop cannot lie in a single plane If this is placed in a uniform magnetic field the force acting on the loop 1 must be zero 2 can never be zero 3 may be zero 4 will be zero only for one particular direction of the magnetic field

D Heat is flowing through two cylindrical rods of the same material The diameters of the rods are in the ratio 1 2 and the lengths in the ratio 2 1 If the temperature difference between the ends is same then ratio of the rate of flow of heat through ther will be 1 2 1 3 2 8 1 A

In the adjoining velocity time graph Velocity A Velocity is decreasing with time B Deceleration is uniform C D A B Time The object has a negative velocity beyond the point All are correct

The earth is assumed to be a sphere of radius R A platform is arranged at a height R from the surface of the earth The escape velocity of a body from this platform is fv where v is its escape velocity from the surface of the Earth The value off is 2006

The speed of a boat is 5 km h in still water It crosses a river of width 1 km along the shortest possible path in 15 minutes The velocity of the river water is a 1 km h c 4 km h CBSE PMT 1998 2000 Odisha JEE 2008 46 3 km h d 5 km h

2 3 Two vectors of equal magnitude inclined at some angle such that the difference in magnitude of resultant and magnitude of either of the vectors is 0 732 times either of the magnitude of vectors If the angle between them is increased by half of its initial value then the magnitude of difference of the vectors is 128 2 5P 3 3P 4 3P

Three copper plates A B C shown below are kept at very small separations If the plate A is given 2 C of charge then the charge on the outer surface of the plate C will be 1 2 C 3 0 5 C 2 1 C 4 Zero A B C

A particle starts from the origin goes along x axis to the point 10 m 0 and then returns along the same line to the point 10 m 0 The distance and displacement of the particle during the trip are 1 20 m 0 2 30 m 10 m 3 30 m 10 m 4 20 m 10 m

Three uncharged capacitors are connected with a battery as show in the figure The work done by the battery in fully charging the capacitors will be 6 F 6 F HH 3 uF 41 O 0 6 J 10 V O 0 3 mJ O 0 3 J O 0 6 MJ mJ

gas is erature while T 17 If hydrogen gas is heated to a very high temperature then the fraction of energy possessed by gas molecules correspond to rotational motion 1 3 35 3 2 4 2 7 T 2

In which of the following cases the transistor is operating in the active region IV 1 3 2V OV OV 2V 2 2V IV OV 8 IV 2V OV 1 3 2V IV IV OV OV 2V 2 2V OV IV 2V OV

In the presence of an inhomogeneous weak magnetic field spectral fines due to transitions between two set of states were observed 1 H and 2 DS 2 P3 2 512 The types of Zeeman effect observed in 1 and 2 respectively are a normal normal c anomalous normal The number of levels into which each of the above four terms split into respectively is a 6 4 10 8 b 4 6 10 12 c 11 9 6 4 d 9 5 12 10 ME b anomalous anomalous d normal anomalous

1 P Q and R are three coplanar forces acting at a point and are in equilibrium Given P 1 9318 kg wt sin 0 0 9659 the value of R is in kg wt CET 1998 a 0 9659 b 2 LICJ d O P 150 0 Q R

or NEET Part 1 poles identical in nature are arranged 19 In the arrangement of concentric she below Find net electric field Q 2 2kP the given figure the ratio of electric field at poir 1 2 is 1 1 2 3 4 3 2R Q2r 3R 2Q 3Q 2 3 4 4 2 3 20 A charged particle of mass m 1 kg and charge horizontal ground at an

A A solid and a hollow sphere of same diameter and same material when heated for the same temperature rise will expand by the same amount R The change in volume is independent of the original mass but depends on original volume

3 1 a b only 2 a b c 3 a b c d only C D INWE V The figure shows the result of an experiment involving photoelectric effect The graph A B C and D relate to a light beam having different wavelength Select correct a Beam B has a highest frequency b Beam C has longest wavelength c Beam A has highest rate of photoelectric emission d Highest momentum is possesed by some electrons emitted by B

9 Ship A is sailing towards north east with velocity 301 50 km hr where i points east and north Ship B is at a distance of 80 km east and 150 km north of Ship A and is sailing towards west at 10 km hr A will be at minimum distance from B in JEE Main 2019 a 4 2 hrs c 3 2 hrs b 2 2 hrs Ud 2 6 hrs

18 The circuit diagram shows a logic combination 18 fer with the states of output X Y and Z given for inputs P Q R and S all at state 1 When inputs P and R change to state 0 with inputs Q and S still at 1 the states of outputs X Y and Z change to P 1 Q 1 R 1 1 1 0 0 3 0 1 0 X 1 Y 0 Z 0 2 1 1 1 4 0 0 1 afais gr sst useft ff P Q R S for at Fria X Y Para R 1 S 1 Z en ufafda da P 1 Q 1 1 1 0 0 3 0 1 0 ufafa EN 1 X 1 Y 0 X YAZ Z 0 2 1 1 1 4 0 0 1 Q

The intensity at the maximum in a Young s double slit experiment is Io Distance between two slits is d 5A where A is the wavelength of light used in the experiment What will be the intensity in front of one of the slits on the screen placed at a distance D 10d

Data for Q No 83 to 84 A gas of N particles is enclosed in a volume V at a temperature T The logarithm of the partition function is given by In Z N In V bN kgT 3 2 where b is a constant with appropriate dimensions If P is the pressure of the gas the equation of state is given by a P V bN Nk T c P V b Nk T The interval energy of the gas is given by a U 1 2 k T c U 3 2 Nk T b P V bN k T d P V b Nk T b U Nk T d U 2Nk

Compute quartile deviation graphically for the following data 20 30 30 40 40 50 20 14 50 60 60 70 10 8 Marks Number of 5 Students 70 above 5

on the temperature range A A solid and a hollow sphere of same diamete and same material when heated for the same temperature rise will expand by the same amount R The change in volume is independent of the original mass but depends on original volume

me nt ne of Shown in the fir are for one complete cycle is Vo 1 2V B TU V Sinusoidal lobes D 14 Vo

Find the mean of the marks obtained by both the groups of students taken together An assesses depreciated the machinery of his factory by 10 each in the first two years and by 40 in the third year and thereby claimed 21 average depreciation relief from taxation department bu the I T O objected and allowed only 20 Show which of the two is right

48 Kinetic Theory 21 If a moles of a monoatomic gas are mixed with 29

i A vehicle is moving at a speed of 30 m s on a circular road of radius 450 m Its speed is increasing at a rate of 2 m s The acceleration o particle at this instant is 1 2 8 m s 3 2 m s2 2 4 m s 4 Zero

A particle of charge per unit mass a is released from origin with a velocity voin a uniform mag field B Bok If the particle passes through 0 y 0 then y is equal to 1 3 2V0 B 2V0 B 2 4 Vo B Vo

An inductor of 5 H and a resistor of 20 Ohm are connected in series with a 1 point voltage supply 24V What is the time required to rise the current to 50 of its final value O 0 25 S O 0 173 s O 0 83 s 0 537 S

Scores of two golfers for 24 rounds were as follows Golfer A 74 75 78 72 77 79 78 81 76 72 72 77 74 70 78 79 80 81 74 80 75 71 73 Golfer B 86 84 80 88 89 85 86 82 82 79 86 80 82 76 86 89 87 83 80 88 86 81 81 87 Find which golfer may be considered to be more consistent player

coherent Two closely located monochromatic sources create a fixed interference pattern on a screen The frequency of one of the sources is then decreased What will happen to the interference pattern as a result The pattern will completely disappear The fringe spacing will increase X The fringes will shift up or down but the spacing will remain constant The fringe spacing will decrease

The sum of the magnitudes of two forces acting at point is 18 and the magnitude of their resultant is 12 If the resultant is at 90 with the force of smaller magnitude what are the magnitudes of forces AIEEE 2002 Kerala PET 2007 b 14 4 d 10 8 a 12 5 5 13

problem after the spring attains it s natural length Xo A m k voorr B th m 20 Maximum elongation in spring during the subsequent motion is Maximum elongation in spring during the subsequent motion is X KXO m Velocity of centre of mass of the system is Maximum speed of block A during subsequent motion be

Find arithmetic mean Draw the ogives and hence estimate the median 10 19 Class 40 49 240 32 0 9 Frequency 8 20 29 142 30 39 216 50 59 206 60 69 143 70 79 13

Two identical cells are connected in a series b parallel then maximum power transfered to the load is 1 Same in both cases 2 Different in both cases 3 May or may not remain same depending upon polarity of the cell connected 4 None

The force of interaction between two atoms is given by XP 2 where x is the distance k is the F a exp 2 a M L T 2 c MOL T4 akt Boltzmann constant and T is temperature and a and are two constants The dimension of Bis JEE Main 2019 46 M LTA d MLT 2

Question 12 A Xt Yt 2 The radioactivity of a sample is X at a time t and Y at a time t If the mean life of the specimen is T number the of atoms that have disintegrated in the time interval t2 t is B X Y C M M 4 00 X Y T N M 1 00 9

At time t 0 a 2290 kg rocket in outer space fires an engine that exerts an increasing force on it in the x direction This force obeys the equation F At where t is time and has a magnitude of 781 25 N when t 1 37 s Choose the correct Sl units of constant A O s N ON s

A stationary hydrogen atom in the first excited state emits a photon If the mass of the hydrogen atom is m and its ionization energy is E then the recoil velocity acquired by the atom is speed of light c 3E A 2 5 c 2m B C Correct Answer 3 3E 4mc 3E 4m c C c C

pop The magnetic field intensity at the point O of a loop with current i whose shape is illustrated below is b 16 3 1 4T 2a Hoi 3 2 Hoi 1 2m a h a b 2 4 Moi 2 4 a 2 0 Moi 1 1 4 a b

Bodies of masses 4Kg and 2Kg are attached at the ends of a massless rod The positions of 4Kg and 2Kg are position of centre of mass of the system is A 12i 8j 3 C 8 i 127 m 8 12j 3 8i 8j 3 m m 21 53 m m and 41 25 m Then the

AB is a wire of potentiometer With the increase in the value of resistance R the shift in the balance point J will be E www A H 1 towards B 2 towards A 3 remains constant 4 first towards B then back towards A

4 None of the above A piece of copper and other of germanium are cooled from room temperature to 100 K 1 Conductivity of copper increases and that of germanium decrease 2 Conductivity of copper decreases and that of germanium increases 3 Conductivity of copper as well as germanium both decreases 4 Conductivity of copper as well as germanium both increases

A uniform bar of length 6a mass 8m lies on a smooth horizontal table Two point masses m 2m moving in the same horizontal plane with speeds 2v and v respectively strike the bar as shown in the figure stick to the bar after collision 2a 2m C 2a m Sm Angular velocity of the rod about centre of mass of the system is

Two particles are attached to light s tring the masses are rotated at const ant angular speed of 5 Radian per se cond about a point A the surface is h orizontal and smooth the ratio of ten sion the inner strength to Outer one i S Q 41 Code A Circular Motion Tension 1 Two particles are attached to light strings as shown in figure The masses are rotated at constant angular speed of 5 radian per second about point A The surface is horizontal and smooth The ratio of tensions in inner string to outer one is 15 4 3 4 3 M 2 3 4 4 1 1 2 M

If you apply the same 50 N force at the halfway point at 12 cm point instead of the 24 cm point between the center of the bolt and the current position how much is the torque is reduced compared with t torque at the 24 cm point a fraction of the onginal torque between 0 and 1 0 See the figure below BAS 24 cm 50 N

A planet moves around the sun along an ellipse so that its minimum distance from the sun is equal to r and the maximum distance to R Making use of Kepler s laws its perio find the value of n of revolution around the sun is given by T SRA 2a R r R r Gm THE

3 PA PB Which of the following statements is true about stationary waves 1 All particle except particles at node execute SHM 2 All particles except particles at node come to their mean positions at the same time 3 All particles at antinodes have same velocity at mean position 4 All of these

5 With the usual notation the following equation 1 S u a 2t 1 is 1 Only numerically correct 2 Only dimensionally correct 3 Both numerically and dimensionally correct 4 Neither dimensionally nor numerically correct

Average speed of a bus measured by six different students is given as follows Student number Speed m s 1st 12 5 m s Column l Mean absolute error A B Mean value C D Percentage error Relative error Which option is correct 2nd 12 3 m s P Q R S 3rd 11 8 m s 0 2 12 3 m s 0 0163 1 63 4th 12 4 m s 5th 12 2 m s Column II 6th 12 6 m s