Physics Questions

Curve representing path of the object 18 If v and a represent velocity and acceleration 18 respectively then v may remains applicable in 1 1 Dimensional motion 2 Projectile motion 3 Circular motion 4 None of the above ime relation

ht 4 None of these If P 2Q then which of the following is incorrect 1 P n 2 Direc 3 Dime 4 All c it be equal to 2 Q ons of P Q must be same at the ions of P and Q must be same he above

48 In the circuit shown current through resistance 2 is i and current through resistance 30 2 is i Find the ratio sting 1 9 1 3 5 1 202 ww 2V 5V 30 2 5V 10 V 1522 ww 3 V 5 V 5 V 2 7 1 4 None of these White

The component of a vector r along x axis will have maximum value if 1 F is along positive y axis 2 is along positive x axis 3 I makes an angle of 45 with the x axis 4 r is along negative y axis

The diagram shows four slabs of different materials with equal thickness placed side by side Heat flows from left to right and the steady state temperature of the interface are given Rank the materials according to their thermal conductivities smallest to the largest d d dd 1 2 3 4 2 1 35 C 30 C 20 C 0 C 15 C 2 1 3 4 3 3 4 1 2 4

Fig Shows a plane mirror onto which a light ray incident If the incidenting light ray is turned b 10 and the mirror by 20 as shown then the angl turned by the reflected ray is 10 TTT 11 300 lockwico 30 reflected ray 7772200 2 30 anticlock wise

20 Two points are at distance r and r from a long string having charge per unit length o The potential difference between the points is proportional to 1 O a o 100 1 2 b log C 4

21 A semicircular wire of radius a having as charge per unit length is shown in the figure Find the electric potential at the centre of the semicircular wire a C 0 480 4TE OR d None of these b

of drop 3 At the top most point 4 Any where is between the poi projection and topmost point 4 A gun is aimed at a target in a line of its The target is released and allowed to fall gravity at the same instant the gun is fired bullet will 1 Pass above the target 2 Pass below the target 3 Hit the target 4

x m 60 50 40 30 20 10 1 2 3 4 5 A 6 t sec B Displacement time curve of two objects A is shown in the figure Find relative velocit B with respect to A 1 15 m s 2 10 m s

Each of the figures below shows 3 blocks of masses 4m 3m and 2m acted on by an external horizon force F For each figure which of the following options is INCORRECT FAB Magnitude of the fo that block A exerts on block B FBC Magnitude of the force that block B exerts on block C Assu that the surface on which the blocks move is frictionless F 1 In figure 1 FAB 3 In figure 2 F AB 5F 9 4F 4m B 3m 2m Figure 1 4m B 3m 2m Figure 2 2 In figure 1 F 4 In figure 2 2F BC 9 Fac BC 5F F

40 Find the force of interaction of two dipoles if the two dipole moments are parallel to each other and placed at a distance x apart a 3P P2 4 E OX 0 7 P b P P2 4 EXA C P2 P P 4 EX 4 d P P2 3 EX 4

A particle is projected from point A A fly is standing at a tower at point B as shown in figure When particle passes from B fly starts flying in horizontal direction with constant speed of 2 m sec Both will meet at the same horizontal level at point C Then g 10 m sec 1 angle of projection is tan 3 angle of projection is 45 9 2 B 2m 4m C 2 angle of projection is tan 2 4 None of these

7 An alternating voltage in volts given by V 200 2 sin 100t is connected to 1 F capacitor through an ideal a c ammeter in series The reading of the ammeter and the average power consumed in the circuit shall be

Three blocks A B C are connected by two strings x y as shown in figure 1 9Kg 4Kg 1 9Kg A 0 1kg X B 0 1kg y t C 2m F Smooth 2m The system is pulled in right direction by force F If breaking strength of strings x y are 10 respectively then maximum value of F for which none of strings will breaks is 2 440N 1 400N 3 300N 4 330N

6 At a place in magnetic meridian magnetic needle bends 30 from horizontal If earth s magnetic field at this place is 2 G then vertical component and horizontal component of earth s magnetic field respectively are a 10T 2x10 T b 10 T 3x10 T c 3x10 T 10 T d 3x10 1 2x10 T

The refractive index of slab shown in figure varies with distance x from face AB as 1 apparent distance of object observed by observer from face CD will be 1 It A 2t B C D 8t 2 12 3 3 VEL sick to viral 4 None of these The

17 velocity of B with respect to A 1 20 m s 2 10 m s 3 10 m s 4 20 m s Variation of quantity P with quantity Q is plotted in given figure describes motion of particle in a straight line Then which of the following statement is wrong P tive Q 1 Quantity Q may represent time 2 Quantity P is velocity if motion is uniform 3 Quantity P may be displacement if motion is uniform 4 Quantity P may be velocity if motion is 17

3 The length of wire when M is hung from it is 1 and is with both M and M hanging The natural length of wire is M 1 1 h 1 M M M 2 M J M M M 4

1 The standard enthalpy of formation of NH3 is 46 0 kJ mol If the enthalpy of 1 formation of H from its atoms is 436 kJ mol and that of N is 712 kJ mol the average bond enthalpy of N H bond in NH3 is a 964 kJ mol 1 c 1056 kJ mol 1 b 352 kJ mol 1 d 1102 kJ mol 1

7 Electron is revolving around a nucleus in circular orbit of radius 1 A with a speed 4 x 10 m s Magnetic moment produced due to rotation of electron is al 3 2x10 20 m b 64x10 A m d 1 6x10 A m c 3 2x10 2A m

An electron has an initial speed of 6 2 x 106 m s at point A The electron moves from point A and stops at point B Find the potential difference VA VB between the two points in volts

A particle is moving along x axis experiences a constant acceleration of 4 m s in negative x direction At time t 3 sec it velocity was observed to be 8 m s in positive x direction The distance travelled by particle in time interval t 0 to t 7 sec will be 1 42 m 2 98 m 3 49 m 4 58 m

3 50 A small object is placed 10 cm infront of a plane mirror If you stand behind the object 30 cm from the mirror and looks at its image the distance focussed for your eye will be 1160 cm 2 20 cm 3 40 cm 4 80 cm

Parallel plate capacitors with a plate sperati on of 1 cm stores 0 02 J of electrostatic en ergy when charged by a battery If it has a c onducting slab between its plates and when charged by a same battery it stores 0 05 Jo f energy Find the thickness of the slab

Ge and Si diodes conduct at 0 3 V and 0 7 V respectively if Ge diode is reversed biased in turn the value of Vo changes by 10 V wwww 9kQ O 05V 04V O 0 3V O OV Ge V Si

3 A motor is fixed inside a box which is moving upwards with velocity 5 m s String is winding at the rate 3 m s Then the velocity of block A will be 1 2 5 m s downwards 3 1 m s downwards 5m s DO mos S 2 5 m s downwards 4 2 m s downwards Space for Rough Work

3 11 6 g cc 4 11 7 g cc 28 Two wires A and B of same material have radii in the ratio 2 1 and lengths in the ratio 4 1 The ratio of the normal forces required to produce the same change in the lengths of these two wires is 1 1 1 2 2 1

s this in syllabus of NEET 2021 44 An amplifier A with a negative feedback is shown in the diagram Choose the correct expression for the close loop gain of the amplifier 1 A Amplifier A 1 AB Feedback ES TESundations 2 4 A 1 AB AB 1 AB Vo

A particle is projected from ground with 25 m s at 37 with horizontal A vertical plane mirror initial at a distance 30m from point of projection is moving away from point of projection with 10 m s The relative separation between particle and its image in plane mirror at t equal to 2sec will be 10m s 1 60m 25m s 2 20m 37 30m wan Silvered Side 3 40m Space for Rough Work 4 10m

If a body is moving along a straight path then which of the following is true Distance is always equal to magnitude of displacement O Body is always accelerated O Distance may be greater than the magnitude of displacement O Speed of body will always be zero once in the journey

1 The mass m collides elastically with mass M The period of oscillation and amplitude of resulting motion of M are respectively m M 1 2T k moooo M M 2mv K m MVK smooth E IM 2my IM m 2 2 m 2mv K m MVK

3 The relations amongst the three elements of earth s magnetic field namely horizontal component H vertical component V and angle of dip 8 are B total magnetic field a V 8 tan 8 H 8 V 8 sind H B cos c V 8 cos8 H 8 sind d V B H B tand

A point charge q is placed at centre of a hollow conducting sphere with radius R carrying a charge Q The potential at a point in a space at a distance r R from the centre of the sphere is A zero B C D Q q 4 4 0 Q q 4 o r R

52 3 5 4 0 When a uniform metallic wire is stretched the lateral strain produced in it is If a and Y are the Poisson s ratio and Young s modulus for wire then elastic potential energy density of wire is E YB 2 Ya 2 YB 20 Yo

ALLEN 16 x m 90 80 70 60 50 30 201 2 3 B 56789 t sec 16 Displacement time graph of two particle A B is shown in the given figure Find relative velocity of B with respect to A 1 20 m s 2 10 m s 3 10 m s 4 20 m s of quantity P with quantity Q

EXAMPLE 14 Sum and Difference Together Consider vectors A and B having equal magnitude of 5 units and are inclined each other by 60 Find the magnitude of sum and difference of these vectors Sol Given A 5 units B 5 units 0 60 A B and A B B R A B A B B 60 120 A R A B Dot Produ Terms of It is defined as and the magnit direction of fir If then a b a a

39 What work must be done to rotate an electric dipole through an angle 0 with the electric field if an electric dipole of moment p is placed in an uniform electric field E with p parallel to E a W pE 1 cos0 c E 2pE 1 cos0 b W pE 1 cos0 d None of these

ABLE MASS SYSTEM Consider at any time t a system of mass m travelling with velocity v as shown After a small time dt let its mass become m dm and velocity v dv Here a small mass dm travelling with velocity u adds into this system of mass m F is the force on r due to an external agent For the system of m dm ext v dv m dm dm U m mdi at time t I Fe du du ext I I Impulse change in momentum Fext dt m dm v dv mv dmu dua at time t dt I 1

A 4 5 cm needle is placed 12 cm away from a convex mirror of focal length 15 cm The position of image and the magnification respectively are 5 2 6 7 cm 1 8 7 1 3 33 cm 3 0 15 cm 1 8 4 6 7 cm 519

9 The magnetic field in a region between the poles of an electromagnet is uniform at any time but its magnitude is increasing at the rate of 0 02 T s A conducting loop is placed in this region whose plane is perpendicular to direction of magnetic field Calculate the emf induced and induced current in the loop Take cross section area of loop as 120 cm and resistance of loop as 5 Q a 0 48 V 0 096 mA b 0 48 mV 0 0096 mA c 0 24 mV 0 048 mA

3 Both 1 and 2 4 Acceleration A ruler is dropped vertically through the gap 14 between your thumb and fore finger Then find reaction time if displacement of ruler is 21 0 cm 1 0 2 sec 3 0 8 sec 2 0 6 sec 4 0 9 sec wing graph represents ruler GEEK FREI Fil ruler fara 1 0 2 sec 3 0 8 sec For y 15 15

Sir in this magnetic flux is changing for every shape beca e magnetic field lines are continuously decreasing theref emf will also change 38 90 77 6 A rectangular a square a circular and an elliptical loop all in the X Y plane are moving out of a uniform magnetic field with a constant velocity V vi The magnetic field is directed along the negative Z axis direction The induced e m f during the passage of these loops out of the field region will not remain constant for 120091 B CY the circular and the elliptical loops only the elliptical loop any of the four loops DY the rectangular circular and elliptical

A block of mass M is hanging from a mass less spring of spring constant k Initially the block is in equilibrium In this position length of the spring is Z Now an agent is holding a point P at a distance of from top and displaces it 3 downwards by a distance of x Find weweeeeeeee M

3 volume of 1 m at a constant pressure of 100 N m Then it is heated at constant volume by supplying 150 J of energy As a result the internal energy of the gas B D decreases by 50 J increases by 250 J Correct Answer decreases by 250 J increases by 50 J EXPLANATION Isobaric process with Q 0 0 W AU

Two capacitors C C and C 3C are connected as shown in figure Initially key K is open and capacitor C holds charge Q after closing the key K the charge on each capacitor at steady state will be C A C Q Q 4 4 3Q 3Q 4 4 B Q 3Q 44 D 2 0 3 C

displacement if motion is uniform 4 Quantity P may be velocity if motion is uniformly accelerated A ball is dropped from a building of height 45m Simultaneously another ball is thrown up with a speed of 40 m s Calculate the magnitude of relative velocity of the balls when both balls are in air 1 0 m s 3 40 m s 2 20 m s 4 60 m s

A ray of light incident at an angle 0 on a refracting face of a prism emerges from the other face normally If the angle of the prism is 5 and the prism is made of a material of refractive index 1 5 the angle of incidence is 1 7 5 2 5 3 15 4 2 5 New Ligh

16 In the arrangement shown in figure block Q is being pulled with constant speed 9 m s in horizontal direction All strings pulleys are ideal then speeds of points A B on string are P A 1 9m s 9m s O 2 9m s 3m s B 9m s Fixed 3 6m s 3m s Vp 9 Vp 2 3 Vp 9 4 9m s 6m s

12 A plastic ball is suspended inside liquid filled in a closed cylindrical container shown in figure The elongation in spring is 1 mm The cylinder is now rotated about vertical axis shown with angular velocity o Assuming that length of spring b a elongation in spring will be 0 A 1 7 mm B 2 mm a C 1 mm D 1 4 mm a