Basic Physics Questions and Answers

Q 16 The position of a particle moving along the y axis is given as y 3t t where y is in metres and t is in sec The time when the particle attains maximum positive y position will be A 1 5 sec B 4 sec C 2 sec D 3 sec Q 17 A ball is thrown vertically upwards from the ground It crosses a point at the height of 25 m twice 1

8 Starting from rest at t 0 a particle moves in a straight line away from the origin with a speed given by v Bt where B is a constant equal to 3 m s How far from the origin is the particle after 2 seconds

A 20m sec B 25 m sec C 30m sec D 35 m sec 18 A particle is projected vertically upwards from a point A on the ground It takes t time to reach a point B but it still continues to move up If it takes further t time to reach the ground from point B then height of point B from the ground is B gt t D 1 2 st t 1 A 8 t 1 C g t g t t

9 A small ball of mass m is released from rest from the position shown in figure The wedge is of equal mass m and friction is absent everywhere The normal reaction exerted on the ball when it reaches the lowest position is 1 3mg 3 Ama R m Smooth 2 2mg 4 5mg

L T1 Answer M T2 Box Mass 75 6 kg T1 15 1 T2 64 3 F 2191 5 N Hdynamic 0 10 Hstatic 0 38 Assume that the box just had an initial velocity of 5 m s and that the above forces are applied over a period of 10 s How far alor the length of the slope will the box travel during those 10 s A ball is dropped from a height of 8 69 m After hitting the ground the ball then rebounds to a height of 5 09 m What is the coefficient of restitution associated with the ball and around impact

A 28 0 kg child slides down a long slide in a playground She starts from rest at a height h of 21 00 m When she is partway down the slide at a height h of 13 00 m she is moving at a speed of 6 70 m s Calculate the mechanical energy lost due to friction as heat etc

3 A particle is thrown horizontally with speed of 30 m s from the top of a tower its speed after 4 seconds is TERY p 1 30 m s 45 m s 3 82 Vy 30410x4 2 4 50 m s 60 m s T

An uncharged conductor A is brought near a positively charged conductor B Ther identify the incorrect statement s among the following A The charge on B will increase but the potential of B will not change B The charge on B will not change but the potential of B will decrease C The charge on B will decrease but the potential of B will not change charge on B will not change but the potential of B will increase TL

A simple pendulum of time period T is suspended above a large horizontal metal sheet with uniformly distributed positive charge If the bob is given some negati charge its time period of oscillation will be A T BY T C T Proportional to its amplitude

In a region of space the electric field is in the X direction and proportional to x i e E Exi Consider an imaginary cubical volume of edge L with its edges parallel to the axes of coordinates The charge inside this volume is

What is the power of a 33 5 cm focal length lens Express your answer using three significant figures P Submit Part B f2 Part C What is the focal length of a 5 25 diopter lens Express your answer to three significant figures and include the appropriate unit 0 Request Answer AEO Value A Roth Is Units BMW Are these lenses converging or diverging D O Both lenses are diverging O The first lens is converging the second lens is diverging

A wheel has a radius of 13 0 cm and is initially at rest The wheel then has a constant angular acceleration of 52 5 rad s2 What will the angular speed of the wheel be when it has been rotating for a time of 16 0 s in units of rad s

60 Uniform rod AB is hinged at the end A in a horizontal position as shown in the figure The other end of the rod is connected to a block through a massless string as shown The pulley is smooth and massless 777 AQ Masses of the block and the a c 3mg g 8 81 mg 5g 8 81 rod are same and are equal to m Acceleration due to gravity is g The tension in the thread and angular acceleration of the rod just after release of block from this position are b m 1 d 1 5mg 3g 8 81 7g 7mg 81 B m

Match the elements of given atomic number with their properties Column I P 11 Q 19 R 37 S 55 Column II 1 IE is maximum 2 Z 2 2 on last electron 3 Size largest 4 Position is next to Kr

BOGART IS AN ADVENTUROUS MAN HE WANTS TO CROSS THE 12 FT PLANK WHICH COEFFICIENT OF FRICTION POINTS A AND B IS Us 0 4 AT WHAT DISTANCE X WILL BOGART START TO REALIZE THAT NOT EVERYTHING IN E HE WILL REALIZE THE PLANK WILL SLIP ASSUME BOGART S WEIGHT AS 85 LB 10 PTS A 15 45 B

3 If the distance as well as the current in each of two parallel current carrying wires is doubled the force per unit length acting between them becomes 1 doubled 3 quadrupled 2 remains same 4 halved

The magnitude of magnetic force per unit length between two parallel wire having currents 12 and placed at distance d apart is given by Fm H L 2nd and the magnitude of electric force between two charges Q and Q2 placed at distance r apart is given by 1 Q Q 4ne The electric resistance of medium depends upon permeability and permitivity e as given below R b Then a 21 1 b 2 1 2 a 21 6 1 12

8 2 All blocks are in equilibrium If block B is pulled upwards very slowly so that lower spring comes to its natural length what is the displacement of block B B A 4mg k B 3mg k Ele Eeeeee 2k A C 2mg k D 5mg k 2 3 RACE

Consider a regular cube with positive point charge Q in all corners except for one which has a negative point charge Q Let the distance from any corner to the center of the cube be r What is the magnitude of electric field at point P the center of the cube 1 2 3 4 E 0 E 1kQ r E 2kQ r F 6k0 r P X Your Answer

62 A uniform rectangular plate of mass m which is free to rotate about the smooth vertical a hinge passing through the centre and perpendicular to the plate is lying on a smooth horizontal surface A particle of mass m moving with speed u collides with the plate and sticks to it as shown in figure The angular velocity of the plate after collision will be a 12u 5a c 3u 2a b d 12u 19a 3u 5a 2a Iu m

3 Dyne 4 Joule Time period t is the function of density p length and tension T The period of oscillation is proportional to 1 p 2 T 1 2 3 p 21 2 3 4 2 23 2 1 2 4 p 21 23 2 Telegraf stion 40 3 3154 a T Enl aguatam E 1 p 2 T 1 2 3 p 213 2 3 4 and f 2 p3 223 21 2 4 p 1 23 2

Two conductors each of length 12 m are parallel to each other in air The centre to centre distance between the two conductors is 15 cm and the current in each conductor is 300 amperes The force in newtons between the conductors is 2 1 44 N 4 0 12 N 1 0 144 N 3 14 4 N

59 A uniform rod is hinged at its one end and is allowed to rotate in vertical plane Rod is given an angular velocity w in its vertical position as shown in figure The value of w for which the force exerted by the hinge on rod is zero in this position is a 3 g b o 2g VL 3g d

An ammeter and a voltmeter are connected in series to battery with an emfE 6 0 volt When a certain resistance is connected in parallel with the voltmeter the reading of the latter decreases to two times whereas the readings of the ammeter increases to the same number of times Find the voltmeter reading CL

16 Potential energy of a particle of mass 1 kg moving 3 x 3 along x axis is given by U 4x 12 where x is in meter For this force field consider the following four statements and identify the correct combination of statements i x 2m and x 2m are positions of equilibrium ii x 2m is the position of stable equilibrium iii x 2m is the position of unstable equilibrium iv Potential energy is minimum at x 2m 1 i ii 2 ii iv 3 i ii iii 4 i ii iii iv 21 The diagr function c The poin 1 3 22 A

2 A potentiometer using cell C of emf 5V and internal resistance 0 2 ohms is connected to a wire AB in the figure below A standard cell CO of a constant emf of 1 10 V gives a balance point at 55 cm of the wire When CO is replaced by a cell of emf E the balance point is obtained at 85 cm What is the value of E O a 1 4 V O b 1 5 V O c 1 7 V O d 1 9 V

61 A uniform rod of mass m length 1 is placed over a smooth horizontal surface along y axis and is at rest as shown in figure An impulsive force F is applied for a small time At along x direction at point A The x coordinate of end A of the rod when the rod becomes parallel to x axis for the first time is initially the coordinate of centre of mass of the rod is 0 0 TC 12 12 0 1 7 2 0 1 a O 10 RIC 6 TAI 1 2 1 2 B X

1 OA 2 OB 3 OC 4 OD A block A with mass 100 kg is resting on another 31 block B of mass 200 kg As shown in figure a horizontal rope tied to a wall holds it The coefficient of friction between A and B is 0 2 while coefficient of friction between B and the ground is 0 3 The minimum required force F to start moving B will be 1 900 N 3 1100 N A B 2 100 N 4 1200 N 1 OA A nam nequesbonpaper 2 OB 3 OC 100 kg fagur feat dan 0 3 B FAR BIR HEF 1 900 N 3 1100 N Referent 0 4 OD A B 200 kg 2 100 N 4 1200 N

particle has initial velocity 15 m s and m s Distance travelled in 8th second is 1 2 m 3 0 5 m 2 30 m 4 56 m 3 1 2 m 3 0 5 m 15 m s 2 m 2 30 m 4 56 m

of a spring and an inextensible string as shown in the figure Force constant of the spring is k The particle is pulled down from its equilibrium position by a distance x and released 111 m String X Spring a Find maximum value of x for which the motion of the particle will remain simple harmonic b Find maximum tension in the string if mg

A body of mass 2 kg is revolving with angular speed 2n radian s in a circular path of radius 1 m The centripetal force acting on body is 8n 47 3n

Figure shows a paper role mounted on horizontal fixed axis Paper is drawn at a constant speed V The thickness of paper is b and r is the instantaneous radius of the roll b r such that the time taken to complete one rotation can be taken as approximately The angular acceleration of the paper roll approximately 2 r V bv is given by a Then a c 2 r

4 Upper part of a prism is cut The ray diagram of a ray incident at first refracting surface is as shown in figure The minimum deviation that can be produced by the prism is a 12 b 16 c 8 d less than 8 36

In the circuit shown in figure calculate the ratio of current i 12 is 292 1 2 3 2 2923 Question Type Single Correct Type 8 8231822 492 0 5 3822 16V 352 www 8V 192

Example 3 31 From the top of a building 16 m high water drops are falling at equal intervals of time such that when the first drop reaches the ground the fifth drop just starts Find the distance between the successive drops at that bas instant wol

SolveLancer Test If the velocity of an alpha particle is 6 of the speed of light Then find the distance of closest approach to nucleus SolveLancer Test a 7 92 x 10 16 m b 8 53 x 10 17 m c 8 53 x 10 15 m d 8 53 x 10 16 m

Q 4 O 34 Liquid is filled in a container Find the value of acceleration a for which point x is exposed to air as shown in the figure 29 L X 4 L4 1 02 57 a

Two balls are rolling on a flat smooth table One ball has velocity components 3 and i while the other has components 21 and 23 If both start moving simultaneously from the same point the angle between their paths is A 15 B 30 C 45 D 60

Using these two equations diameter of planet can be calculated Example 2 1 Calculate the angle of 4 1 degree 1 second of ar or are second in radians Use 360 2x rad 1 60 and 1 60 Solution a We have 360 2n rad 50 b 1 minute of arc or arc min I 180 1 60 1 745 10 2 rad 1 2 908 10 rad 2 91 x 10 4 rad 1 rad 1 745 10 2 rad

A body of mass 3 0 kg starts from origin with an In velocity u 30i 40 m s If a constant force 67 5j N acts on the body then the time in whic component of velocity becomes zero is 15 s 5 s 24 s

er in a river is flowing with velocity 2 respect to ground and boat is movin j m s with respect to ground The t with respect to river water is 6i 2 m s 27 2 m s 21 2 m s 21 41 m s

small stone is released from rest from the top of a multi storey building During its free fall the ratio of e distances moved by it during 1st 2nd and 3rd second of its journey will be b 1 3 5 1 2 3 c 1 2 3 d 1 1 1

Four solutions A B C and D turn pH paper red yellow green and blue respectively Which of the following is the aqueous solution of sodium oxide Radu A B C PH GRI T A

Two masses 2m and m are whirled in a circle The radius of path of 2m is rand shown in figure Then the ratio of tensic strings are O 2 1 1 1 3 4 2m m

0 Yin I 8 85 x 10 x 3 14 2 78 x 10 Problem 3 It has been experimentally observed that the electric field in a large region of the earth s atmosphere is directed vertically down At an altitude of 300 m the electric field is 60 Vm At an altitude of 200 m the field is 100 Vm Calculate the net amount of charge contained in a cube 100 m on edge located between 200 m and 300 m altitude Solution Let I be the edge of the cube which is equal to 100 m 1 E 60 Vm 100 m

4 41 A tennis ball is thrown from a height h above the ground If the coefficient of restitution is e what height will V the ball achieve after the third collision 1 he6 3 he 2 he 4 he

A variable condenser is permanently connected to a 100 V battery If the capacity is changed from 2 F to 10 F then change in energy is equal to 1 2 102 J 2 2 5 x 10 J 3 3 5 102 J 4 4 10 J

An unknown resistance R is connected in series with a resistance of 10 22 This combination is connected to one gap of a metre bridge while a resistance R is connected in the other gap The balance point is at 50 cm Now when the 10 22 resistance is removed the balance point shifts to 40 cm The resistance is removed the balance point shifts to 40 cm The value of R is 1 1022 3 40 92 2 20 92 4 60 92

Four identical pendulums are made by I made by attaching a small ball of mass 100 g on a 20 cm long thread and suspended from the same point Now each ball is given charge Q so that balls move away from each other with each thread making an angle of 45 from the vertical The value of Q is close to 1 9 109 in SI units x 41 0 A 1 C C 2 C 19 Nov 2017 B 1 5 C D 2 5 C

A B FILL IN THE BLANKS WITH THE HELP OF WORDS GIVEN IN THE BOX Record Audio Animate Delay Action is used for adding various effects to a presentation option EXERCISE 1 2 Audio drop down arrow displays 3 4 5 1 2 3 buttons are basically used to create hyperlink in a presentation means adding motion or special effects to something will play the animation after a certain number of seconds WRITE TRUE T OR FALSE F Video drop down arrow displays three sub options Hyperlink means that the presentation will go to the specified page Entrance option is used to emphasize on a par Forma