Physics Questions

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

two A long cylindrical iron core of cross sectional area 5 cm is inserted into a long solenoid having 2000 turns and carrying a current 2A The magnetic field inside the core is found to be 1 57 tesla Neglecting the end effect the pole strength developed 1 325 A m 2 625 A m 3 125 A m 4 425 A m

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

The coordinate of a point where parallel rays are focussed by the thin convex lens is where focal length of convex lens is 10 cm and it is placed along y axis WENKE 45 1 10 10 cm YA ENDERE P O C NS 2 10 20 cm

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

In adjacent diagram the ratio of mass m and m m m so that they remain at rest given all surfaces are smooth and inclined faces are fixed is 16 X Value of x is wwwwwww m 37 m 53

A body travels the distance AB with speed 2 m s Thereafter it travels BC with speed 1 5 m s and the remaining CC 1 1 with 0 5 m s Calculate the averag speed for this journey assuming that t body takes some time in travellin distances BC a CC same 2x2x1 3 1 2 m s 2 1 33 m s 3 0 66 m s 2M 3 AH

The diagram shows a concavo convex lens of RI What is the condition on the refractive indices so that the lens is diverging 2R 1 2u3u 1 3 3 2 F Hz R 2 2 3 4 None of these

40 electric field line if in the electric field of a source charge Q The test charge will not follow path of Fixed Source Test charge charge 1 It has zero velocity when released 2 It has non zero velocity along outward radius when released 3 It has non zero velocity along inward radius when released It has a velocity different

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

29 A car P is moving with a uniform speed of 72 km h towards another car Q at rest on a straight level road At a particular instant when the distance between P Q is 525 m the car Q started accelerating at 2 m s towards P Find the distance travelled by Q when both the cars meet 525 1 300 m 2 20 2 225 m 525 3 100 m 4 30 m x t P 20m 5 23 12 XO 525m

The electric field at the origin is along the positive x axis A small circle is drawn with the centre at the origin cutting the axes at points A B C and D having coordinates a 0 0 a a 0 0 a respectively Out of the points on the periphery of the circle the potential is minimum at a A b B c C d D

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

When the angle of incidence on a material is 60 the reflected light is completely polarized The velocity of the refracted ray inside the material is in ms 1 3 108 3 3 108 3 4 0 5 108 2 108

A hydraulic lift is designed such that cross sectional area of its arms are 5 cm 10 m Find the force applied by mechanic or smaller area in order to lift a car of 5000 kg A B C 5 N 2 5 N 10 N 12 N

Two cars A B start from rest from the same point in same direction with acceleration 8 m s2 4 m s respectively then acceleration of car B in frame of A Take direction of motion of car is positive In the previous question when distance between both cars becomes 200 m find distance travelled by the car A in ground frame

When the nucleus of an atom absorbs one of the atom s orbital electrons the process is known as k capture Which equation in which X denotes the appropriate particle represents this process A B C 55 Fe 63 Ni 55 X 25 Mn X Cu 63 29 10B B X U He 5

A particle of mass m describes a circle of radius r The centripetal acceleration of the particle is 4 r2 The momentum of the particle is O 4m O2m EN O 4m O2m

One mole of an ideal the process AB as shown in the T V indicator diagram If volume of the system changes from Vo to 0 2V then the amount of heat transferred to the system is 5RV a c 2 5RaV 0 RT In 2 monoatomic gas undergoes T To 0 b RT ln2 d V 0 0 2 3RaV B tan0 a 2V0 3RV RT In2 V RT ln 2

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

marks A string is wrapped round a log of wood and it is pulled with a constant force F as shown in the figure Tension in the string increases with increase in 8 Tension T in the string decreases with increase in 8 Tension T Fife m 3 Tension T Fife m 4 F

A Q4 Two battries of emf 1 2 and internal resistance r r2 as shown in figure The effective emf of the circuit acr 1 1 2 3 4 1 1r1 2r2 r r E1r2 2r1 r r2 E1r2 2r1 r1 x r2 E1r1 2r2 r1 r2 1 11 2 B Subtopic Grouping of Cells 12 3 From NCERT 4

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

3 After the switch is closed the current will increase in which resistor s 252 352 492 552 A 192 B C D E 10 20 30 40 Lit

marks For a particle of mass 1 kg moving with a constant acceleration in any interval of time when initial and final velocities are u and v the average velocity is u v 1 2 the average velocity is u v 2 the average kinetic energy 2 U IS 1 u uv the average kinetic energy is

A proton and an a particle are accelerated through a potential difference of 100 V The ratio of the wavelength associated with the proton to that associated with an a particle is 1 2 1 2 2 1 3 2 2 1 4 2 2 1

According to Bohr s theory the energy of an electron in hydrogen atom in states corresponding to n 1 2 3 4 is repsectively 13 6 eV 3 4 eV 1 51 eV and 0 85 eV In order to obtain emission of HB line of Balmer series the minimum energy that has to be given to a normal hydrogen atom is 1 12 75 eV 2 14 45 eV 3 2 55 eV 4 4 25 eV

Three travelling waves in same direction are superimposed The equations of wave are y Ao sin kx wt y 3 2A sin kx cot and y3 4A cos kx wt If 0 2 and the phase difference between resultant wave and first wave is 4 then is

Problem 7 8 A certain cloud consists mostly of supercooled wa ter droplets at 10 C and maintains the ambient air at saturation with respect to liquid water at that temperature Compute the su persaturation in percent with respect to a solitary ice particle that spontaneously forms in the cloud Answer 10

Pulleys P and P are smooth and fixed The light pulley P is moving upwards by applying a forc F of 120 N The pulley P is also light and movable Block A B and C of their respective masses kg 2 kg and 3 kg are initially placed at the smooth horizontal surface Then choose the correc options g 10 m s 7777 A The acceleration of block A is 50 m s B The acceleration of block B is 5 m s P2 C The acceleration of block C is zero D The pulley P has non zero acceleration P3 BC

ns 1 Activity of a sample is A at time t If it s activity is at time t then find the average life 5 t t n5 1 1 A Ao et A 2 Ae 5 en 5 t 1 t t n5 2 Radio active decay law n5 t t 3 n5 t t 4 t t ble

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

Negative Marks Two moving particles P and Q are 10m apart at a certain instant The velocity of P is 8 m s making 30 with the line joining P and Q and that of Q is 6 m s making 30 with PQ in the figure Then the angular velocity o respect to P in rad s at that instant is O 0 O 0 1 1 In all other cases O 0 4 P 30 10m 8m s Q 6m s 30 Sav

Which of the following is always true regarding the change in entropy of an ideal gas during an isothermal process The change in entropy depends only on the amount of heat transferred The change in entropy is inversely proportional to the temperature The change in entropy is positive The change in entropy is negative

4 Assertion In parallel LCR circuit anti resonance can take place Reason Anti resonance takes place if inductive and capacitative reactances are equal and opposite a

15 Consider a monochromatic linear source of light which is placed at a distance of r from a very small metal plate Due to photoelectric effect electrons are ejected at rate N per second and it is found that maximum kinetic energy of photoelectron is K If source is brought closer to a the rate of emission and the r distance maximum kinetic energy of of photoelectron become nearly 1 F 3K 3 3N K 3 2 3N 3K 4 3N K

The magnetic field strength due to a short bar magnet on its axial line at a distance y is found to be B Find the magnetic field strength at the same distance on the equatorial line A B C B 2B B 2

A bomber flying upward at an angle of 53 with the vertical releases a bomb at an altitude of 800 m The bomb strikes the ground 20 s after its release If g 10ms 2 the velocity at the time of release of the bomb in ms is 2 1 400 2 800 3 100 4 200

When a mass M is attached to the spring of force constant k then the spring stretches by length 1 If the mass oscillates with amplitude 1 what will be the maximum potential energy stored in the springs 1 H 2 2 kl 3 Mgl 4 2 Mgl

PARAGRAPH Relation b w friction and applied force for a block of mass 2 kg on rough horizontal surface is given by below graph 27 28 fL 20 NL fk 18 N Friction O Applied force Find the value of frictional force if applied force on block is 10 N A 20 N B 18 N C 10 N D O Find the value of acceleration of block if applied force is 30 N A 8 m s B 5 m s C 6 m s R 4 m s

Q69 A cell of negligible resistance and e m f 2 volts is connected to a series combination of 2 3 and 5 2 The potential difference in volts between the terminals of 3 resistance will be 1 0 6 V 2 2 3 V 3 3 V 4 6 V 84 From NCERT PMT 1976 1 2 Subtopic Grouping of Cells 3 4