Physics Questions

An object is launched from a cliff 20 m above the ground at an angle of 30 above the horizontal with an initial speed of 30 m s How far does the object travel before landing on the ground in metre 1 20 2 20 3 3 60 4 60 3

A ship of mass 3 x 107 kg initially at rest is pulled by a force of 5 x 104 N through a distance of 3 m Assume that the resistance due to water is negligible the speed of the ship is A 1 5 ms B 60 ms C 0 1 ms 1 A force of 5N acts on a body of weight 9 8N What is the acceleration produced in D 5 ms

D 14 35 180 Ramesh joined the class XI by one week late He missed the concepts of units and measurements chapter in physics Teacher asked him a question for checking his knowledge of rule of significant figures Teacher gave to calculate the result of 9 0 1 7321 Ramesh told him that result contains two significant figures while another student Suresh said that result contains three significant figures Then Ramesh is right Suresh is wrong Suresh is right Ramesh is wrong Both are right Both are wrong Solution Answer 2 Hint Use significant rule of addition Sol 9 0 1 7321 10 7321 With correct significant rule result 10 7 Le result have three significant figures

Figure shows three identical particles connected to massless rods forming an equilateral triangle System is spun and projected under gravity velocity of projection is in plane of figure Acceleration of centre of mass of assembly is g Centre of mass of assembly moves along a parabolic trajectory Each particle follows a parabolic trajectory Rods have no tension m m m

Two long conducting bars P and Q are fixed parallel to each other in a horizontal plane some distance apart On these bars two parallel Jumpers J and J each of resistance R are arranged at seperation x as shown in the figure The Jumpers can slide on the bars with out friction At some point of time a uniform vertical magnetic field is switched on field strength is B Find final seperation between the Jumpers The force between the Jumpers due to their currents is negligible as compared to the force of interaction between current in the Jumper and the magnetic field coefficient of restitution between Jumpers is 0 5 B w x C 2x0 3 D NX

A parallel plate capacitor of separation d is deformed as shown with 1 1 d or d or d for the capaci tance to remain unchanged a 1 d l d c d l d l d d d d l d hd h h d b l d b d d d d do antog A zia A M 12 rob en

40 A coil having n turns and resistance R is connected with a galvanometer of resistance 4R The combination is moved in time t such that magnetic flux per turn changes to flux 2 per turn The average induced current in the circuit is 1 2 3 92 91 5Rnt n 5Rt 02 01 Rnt n 2 1

An observer with a mass 10kg moves at a constant velocity of 10 m s A constant force then acts for 4 seconds on the object and gives it a speed of 2m s in opposite direction The acceleration produced in it is A 3 m s B 3 m s C 0 3 m s D 0 3 m s

35 The current through the external resistance R 402 as shown in the following circuit is 10 V 202 1 Zero 3 5 A ugh Work 20 V ww 4Q ww R 4Q 2 2 5 A 4 8 A

from a clif A ball is thrown horizontally such that it strikes the ground after 5s The line of sight makes an angle 37 with the horizontal The initial velocity of projection in ms is 1 50 100 2 T 3 100 F 4 100

A ball of mass m is projected from a point P on the ground as shown in the figure It hits a fixed vertical wall at a distance from P then after only collisia with wall PO u the ball will return to the point P if half of the horizontal range and collision is elastic the ball will return to the point P if half of the horizontal range and collision is partially elastic the ball can not return to the initial point if half of the horizontal range and collision is partially elastic the ball may return to the initial point if the collision partially elastic and half of the range

5 A particle moving in a straight line along points P Q R has an instantaneous velocity of 10 m s at a point Q The point P is 2 seconds before Q and point R is 2 seconds after point Q The particle has an acceleration of 2 m s2 Find the distance in meters between P and R

Find minimum force required to applied to the trolley of mass 9m so that blocks of masses 4m and m remain stationary with respect to the trolley Ground is smooth Coefficient of friction between each block and trolley is 0 2 A mg 3 2mg 3 B C mg D 4mg 3 Smooth Am 9m m

Estimate the surface energy in Joules per square meter for a covalently bonded crystal silicon diamond structure for a plane parallel to 100 The bond energy of Si Si is 224 kJ mol of bonds and the lattice constant a 0 5431 nm 5 431

o Bok 4 E B K 35 Relation between electric field and magnet field in electromagnetic wave is ECB wher c speed of light in vacuum Ratio of energ density in electric to the magnetic fields is 1 c 1 3 C 1 2 1 c 4 1 1

Test 4 Code A 7 In the circuit shown below if the tap key K is pressed at time t 0 then which of the following statements is false K ww 500 2 500 0 6 F 1000 1 At time t 0 current delivered by battery 4 mA 2 At time t x current delivered by battery 2 mA 3 At time charge on capacitor 6 C

shape of square is placed in a variable magnetic field which varies at the rate of dB as shown in figure The magnitude of emf dt between points a and d along path abcd will be 1 L2 dB 2 dt 2 L2 dB dt 3 2 L dB dt 4 3 L2 dB 2 dt A d dt 34 35 36

32 In the following circuit diagram the value of i i is 222 www ing 20 V 1 2 A 3 8 A 29 www www 352 www 1092 422 2 4 A 4 6 A 10 V

corner of 73 Three identical charge Q are a equilateral triangle What should be the minimum velocity given to charged particle q placed at the centre of the triangle to escape from the electric field of identical charges m mass of charge particle at centre of Qq 3 7 2 4 Im 3 3Q9 37 2 1 Q 9 2 1 Q Qq 3 V 2 2re Im S 1 300 57 1 2

62 Two conducting spheres each given a charge q are kept far apart as shown The amount of charge that crosses the switch s when it is closed is 1 q 3 3 3q 4 q R 9 2R 2 29 3 4 Zero

Two particles A and B are at corners of the field A moves with velocity 3 m s at an angle of 60 to the line AB Find the angle in degree made by B with AB so that it catches A Assuming speed of B as 3 3 m s

20 Two particles A and B are initially 40 m apart A is behind B Particle A is moving with uniform velocity of 10 m s towards B Particle B starts moving away from A with constant acceleration of 2 m s2 The time at which minimum distance between the two occurs is AK A 2 s C 5 s UA 10ms 40 m B B 4 s D 6 s UB 0 B 2 ms

11 In the circuit shown R 10 02 R 20 2 R 30 2 and R 20 02 Potential difference between b and d Vb Vd is b 1 1 V 2 2 V 3 3 V R R 15 V R R

rotation 27 An electron with mass m velocity v and charge e describing half a revolution in a circle of radius r in a magnetic field B will experience change in energy equal to 1 1 mv 4 1 2 Brev

If the Ka radiation of Mo Z 42 has a wavelength of 0 71 calculate wavelength of the corresponding radiation of Cu i e Ka for Cu Z 29 assuming b 1 1 2 52 2 1 52 A 3 1 98 4 3 22

An object is thrown vertically upward Which one of the following statements is false At the top of the trajectory the acceleration vector is zero When the object is moving downwards the velocity vector and the acceleration vector are in the same direction When the object is moving upwards the velocity vector and the acceleration vector are in opposite directions At the top of the trajectory the velocity vector is zero

sphere B made of n size If charge on ers of a 27 The energy stored in 2 F capacitor as sh the circuit in steady state will be 1 4 J 3 0 5 J 4 V HAV F 2 F wwwww 132 152 ww 202 www 2 2 J 4 1 J

NT W AB WA AC WAD ev 27 0 V eV 18 0 V OV B 36 0 V the work W in electron volts done by the electric force on an electron that moves from point A to point B Similarly find W AB 45 0 V D 54 0 V 63 0 V 81 0 V AC WAD and W AE Assume the electron starts and stops at rest Enter your answer

ALONG WITH SOLUTION PLZ TELL ME WHAT APPROACH AN D WHICH METHOD SHOULD I TAKE IN WHAT WAY TO SOLV E FOLLOWING QUESTION AND ALL SUCH QUESTIONS OF T HIS CONCEPT a 30m long ladder weighing 200 kG leans on a frictionless wall with feet 1 m from wall base Find all reaction forces MY MAIN CONFUSION IS ABOUT TAKING EQUATING TORQU E ON BOTH SIDE PLZ ELABORATE THAT PART

Find the true correct statements from the following During clear nights the temperature rises steadily upward near the ground level Two spheres of the same material have radii 1m and S and temperatures 4000 K and 2000 K respectively The energy radiated per second by the first sphere is greater than that radiated per second by the second sphere The total energy emitted by a black body per unit time per unit area is proportional to the square of its temperature in the Kelvin scale Newton s law of cooling an approximate form of Stefan s law is valid only for natural convection

If velocity of an electron in third energy level of a hydrogen like atom is v then velocity of electron in fifth energy level is Only one correct answer A B C 3v 5 9 25 25 V

ect band gap semiconductor 16 op Hence correct option is d If relative density of tungeston is 18 8 gm cm and its atomic weight is 184 assuming that at room temperature there are two free electrons per atom calculate the density of free electrons n Soln Let volume 1 cm G

Half part of ice block is covered with black cloth and rest half is covered with white cloth and then it is kept in sunlight After some time clothes are removed to see the melted ice Find the correct statement from the following Ice covered with black cloth will melt more Ice covered with white cloth will melt more Equal ice will melt under both clothes It will depend on the temperature of surroundings of ice

There is a rough black spot on a polished metallic plate It is heated upto 1400 K approximately and then at once taken in a dark room Th find true statement from the following The plate and the black spot can not be seen in the dark room The spot and the plate will be equally bright In comparison with the plate the spot will appear more black In comparison with the plate the spot will shine more

iTutor All India Aakash Test Series for NEET 2021 21 Five point charges of charge Q each are placed at vertices of a regular hexagon as shown in the figure The direction of electric field at centre O is directed along A 1 OA 2 OF Q B Q F O C E3 Q D Q

27 Two similar very small conducting spheres have charges 40 C and 20 C and are at a certain distance apart Now they are touched and kept at same distance The ratio of initial force to final force between them is 1 8 9 3 1 9 2 8 1 4 7 8

28 Two non interacting inductors L 2 mH and L 5 mH are connected in parallel then respective ratio of 1 Flux is 1 1 2 Current is 5 4 3 Energy is 25 4 4 Energy is 4 25 L mm L mmm

B 60 ms C 0 1 ms D 5 ms A force of 5N acts on a body of weight 9 8N What is the acceleration produced m sec D 0 51 A 49 B 5 C 1 46 Ram and Sam are pulling at the two ends of a rong with

1 7 pts A man runs at a constant speed of v 5 m s along a straight road A car that was initially at rest starts moving toward the runner at the moment when the distance between them is d 200 m as shown in the figure As the car moves toward the runner it gradually increases its speed with a constant acceleration of magnitude 0 50 m s a Write the kinematic equations for position x and velocity v 1 for the runner b Write the kinematic equations for position x and velocity v r for the car c From the moment it starts moving how much time does it take for the car to reach the runner d What distance will the car have traveled when it reaches the runner e What is the speed of the car when it reaches the runner

The round weightless bar in the figure is in in diameter E 30 106 psi The applied load is 5700 lbf Find the tensile stress in t bar and the deformation caused by the applied load 2 0 ft The tensile stress in the bar is psi The deformation caused by the applied load is applied load x 10 3 X in

The four arms of a Wheatstone bridge as shown in figure have resistances as indicated Calculate the current through conducting arm BD B 202 as EE F Ed 35 at Su 3 A 1002 A 60 D 492 10 V 2 48 91 C A 4 16 A

11 Two identical particles move towards each other with 11 0 yelocity 2V and V respectively The velocity of centre Chass is 505 i N 1 35 36 4m vo 1 V 3 V 72 2 V 3 2 10 6 N m 4 16 3 N m 11 V 4 zero 12 Af energy density of gas is 36 l m in an ideal gas then 12 fe the pressure of ideal gas is 24 N m 160 I I 3 40 N m 13 A scientist claims to have developed efficient engine while 13 working between 27 C and 327 C Then efficiency of engine will be Ab 100 bb X 300 Goo Energy 36 V 2 1 24 N m 3 40 N m a t at gerar sit 1 70 2 4 V 3 nf 27 C a 327 C 2 10 6 4 16 3 2 60 4 40

Question No 18 If root mean square speed of hydrogen molecules at 300 K is 1930 m s then at 900 K evaluate the root mean square speed of oxygen molecules 1930 3 643 m s 1930 3 m s 836 m s m s W

A police van moving on a highway with a speed of 30 km h and a thief s car speeding 2 away in same direction with speed is 192 km h Thief in the car fires bullet on police van If muzzle speed of bullet is 150 m s then the speed with which bullet hits the w r t police van is NCERT Pg 58 2 130 m s 1 145 m s 3 115 m s 4 105 m s The acceleration of a body starting from rest

3 4 5R A particle of mass m is projected from orly speed u at an angle 8 with positive x axis Posit y axis is in vertical upward direction Find angular momentum of particle at any time tab O before the particle strikes the ground again 1 m ucose gtk 2 m ucose gt k

The power dissipated in the following circuit will be about half of its maximum value at approximately 1H 100 Q 50 sinof 1 w 1050 rad s 2 w 1000 rad s 3 W 950 rad s 4 Both 1 3

A toy cannon uses a spring to project a 5 40 g soft rubber ball The spring is originally compressed by 4 91 cm and has a force constant of 7 95 N m When the cannon is fired the ball moves 14 1 cm through the horizontal barrel of the cannon and the barrel exerts a constant friction force of 0 031 0 N on the ball a With what speed does the projectile leave the barrel of the cannon 1 389 m s b At what point does the ball have maximum speed cm from its original position c What is this maximum speed m s

26 Two insulating rods of equal length R one of charge q and other of charge q form a circle of radius R one rod forms one half of the circle The electric field at centre of circle is 1 Zero 2 JE 3 9 2 ER 4 9 4TE 9 ER

Two athletes A and b participated in a race along a circular path with constant speed o f 11 m s and 13 m s respectively B reache s the finish line in 2 seconds earlier than a what is the radius of the circular path

3 F F A thin circular ring of mass M and radius r is about its axis with a constant angular velocity w Two objects each of mass m are attached gently to the opposite ends of a diameter of the ring The ring now rotates with an angular velocity 1 2 3 4 M m M 00 M 2m M 2m COM M 2m M 2m