Basic Physics Questions and Answers

In the circuit shown C C 2uF Capacitor C is charged to 50 V and C is charged to 20 V After charging they are connected as shown When S S and S3 are closed Select correct statement s A 70 C of charge will pass through S B Potential difference across C2 is 15 V C 70 C of charge will pass through S3 D charge on right plate of C is 30 C 50V 20V

A charge particle g m is projected from origin at t 0 with velocity vo making an angle of 37 with x axis in x y plane A uniform magnetic fie Boi exists in the region Find the distance of the particle from origin at Am qBo 37 4mvo2 9 5qBo 3mvo2 9 5qBo mvo qBo X

A uniform cylinder of length L and mass M having cross sectional area A is suspended with its length vertical from a fixed point by a massless spring such that it is half submerged in a liquid of density at equilibrium position When the cylinder is given a downward push and released it starts oscillating vertically with a small amplitude The time period of the oscillations of the cylinder will be 1 smaller than 2 3 larger than 2 71 2 M k Aog 1 2 M k Aog 2 2 4 2T M k M k Aog 71 2 2013

117 Smooth F 24 N In the arrangement coefficient of friction between 1 the two blocks is The force of friction acting 2 between the two blocks is 1 8 N 2 kg 4 kg 10 N 2 6 N 4 12 N se

Two rods B and C having same length and made of the same material are being pulled by a pair of oppositely directed axial force of equal magnitude If the cross sectional areas of rod B and C be A and 2A respectively then consider the following statements correct 1 Ratio of extension in rods B and C is 2 1 2 Ratio of extension in rods B and C is 1 2 S Ratio of energy stored per unit volume in rod B and C is 4 1 4 Ratio of energy stored per unit volume in rods

An old man is unable to see objects beyond 40 cm Which lens should he use so that he can see distant objects clearly A Convex lens of power 1 5 D B Concave lens of power 2 5 D C Convex lens of power 2 5 D

A thin equiconvex lens made of glass n is 2 placed in such a way that one surface is in 4 contact with water n and another surface is 3 in contact with air Find focal length of setup if the rays are incident as shown Radius of curvature R 30 cm air 1 60 cm 3 30 cm glass water 2 120 cm 4 100 cm

The resistances in the left and right gaps of a meter bridge are 100 and 30 respectively If the bridge is balanced then the distance of the null point from the centre of the wire is YOU A 20 cm B 30 cm C 40 cm D 25 cm

8 A 2 cm long object is placed at a distance of 100 cm from a convex mirror of radius of curvature 50 cm Find the position nature and length of the image Ans 20 cm behind the mirror virtual 0 4 cm

For the circuit shown in the figure R 2R When R is increased from 0 to infinity current through the battery changes from A to 4 R R www b D 1 R 18 V When value of resistance R is equal to zero then MIN wwww R Current in abis A flowing from a to b Read Less

A conducting rod of length 21 is rotating with its constant angular speed o about perpendicular bisector A uniform magnetic field B exists parallel to the axis of rotation The e m f induced between two ends of the rod is B

5 35 Two coherent point sources of light having wavelength are seperated by a distance d A circle is drawn in space surrounding both the point sources as shown The plane of circle contains both the point sources The distance d between both the sources is given in column I and the total number of corresponding points of maximum intensity and minimum intensity on the periphery of the shown circle are given in column II Match each situation of column I with the results in column II Column I A d 99 4 A B d 99 6 x C d 100 D d 100 42 S S Column II p 398 points of maximum intensity q 400 points of maximum intensity r 396 points of minimum intensity s 400 points of minimum intensity t 402 points of maximum intensity

An object is placed in front of a screen and a convex lens is placed at a position such that the size of the image formed is 9 cm When the lens is shifted through a distance of 20 cm the size of the image becomes 1 cm The focal length of the lens and the size of the object are respectively 750

ring of mass 200 gram is attached to one end of a ght spring of force constant 100 N m and natural length 10 cm The ring is constrained to move on a rough wire in the shape of quarter ellipse of major axis 24 cm and minor axis 16 cm with its centre at origin The plane of ellipse is vertical and wire is fixed at points A and B as shown in figure Initially ring is at A with other end of spring fixed at origin If normal reaction of wire on ring at A is zero and ring is given a horizontal velocity of 10 m s towards right so that it just reaches point B then select the correct alternative s g 10 m s Y 8cm A m lllllll rough wire X B 12cm A Work done by friction is 10 Joule B At B energy stored in spring is more than energy stored at A C Work done by friction is 10 16 Joule 6

A composite conductor of uniform area of cross section carries current lo as shown Conductivity of left half is and that of right half is 02 Then Take permittivity of both the material on left half and right half to be o 7 2 01 A Current density in both the halves is same Current density in both the halves is different Charge on the interface AA is solo 0 01 0102 Charge on the interface AA is 280 0 02 01 0102

cosity A solid homogeneous cylinder of height h and base radius r is kept vertically on a converyer belt moving horizontally with an increasing velocity v a bt If the cylinder is not allowed to slip find the time when the cylinder is about to topple 1 gr 2bh 3 bh 2gr 2 gr bh 4 bh gr

A hospital uses and ultrasonic scanner to locate tumours in a tissue the operating frequency of the scanner is 4 2 MHz The speed of sound in a tissue is 1 7 kms The wav length of the sound in the tissue is close to A 4 10 m B 8 10 m C 4 10 m D 8x10 m

Oscillating metallic pendulum in a uniform magnetic field directed perpendicular to the plane of oscillation 1 Point Slows down becomes faster remains unaffected oscillates with changing frequency

In the spherical coordinates the direction points O 1 South to North O 2 West to East O 3 Radially outward 4 North to South In spherical coordinates the vector points O 1 East to West O 2 North to South O 3 Radially outward O4 South to North In cylindrical coordinates the vector points O 1 Radially inward O 2 North to South O 3 East to West O 4 None of these

3 voor m Block of mass m is pushed against a spring and is then released Find the initial compression in the spring so that block presses the track with a force mg when its reaches the point P The track is smooth 3mgR 1 2 3 2mgR mgR 00000 m afa gefin f ti afe va a far fa 1 2 3mgR k 2mgR k ImaR fata carax ste fear and a fema f ar f f

A tuning fork produces 4 beats sec with another tuning fork B of frequency 288 Hz If fork is loaded with little wax no of beats per sec decreases The frequency of the fork A before loading is 1 290 Hz 2 288 Hz 3 292 Hz 4 284 Hz

a Derive the expression for the maximum safe speed for a car negotiating a circular banked road b Two masses of 5 kg and 3 kg are suspended with help of massless inextensible strings as shown Calculate T and T when whole system is going upwards with acceleration 2 m s Take g 9 8 ms 2 T 5kg

The figure given below shows a balanced Wheatstone s network Now it is disturbed by changing P to 112 Which of the following changes will not bring the bridge to balance again P 1022 www R 2002 C Q 10092 S 20002 A Increasing R by 20 YOU B Increasing Q by 100 Increasing S by 200

The electric field is given as E yi xj N C The work done in moving charge 4 C from A 21 2j m to TB 4 j m is 6 J 9 J 12 J Zero

Two point charges 50 C and 25 C are 20 cm apart as shown The work done to displace 25 C charge from B point to C will be A 50 C 20 cm 11 25 J 16 45 J 9 29 J 3 25 J 90 15 cm 25 C B

A horizontal force of 10 N is necessary to just hold a block stationary against a wall The coeffic of friction between the block and the wall is 0 2 The weight of the block is 1 a 20 N b 50 N c 100 N d 2 N 10N

View In English Two identical capacitors each of capacitance 5 F are charged to potentials 2kV and 1 kV respectively The ve ends are connected together When the ve ends are also connected together the loss of energy of the system is 1 2 3 4 orrect Answer 4 tatu unattemptod 160 J OJ 5J 125 J

4 intrinsic 15 Following diode circuit repersent A Bo 1 OR Gate 2 NOR Gate 3 AND Gate D KH D N www z R Vcc

magnetic Bo exists In region a r 2a A charge particle q m is projected from a 0 with velocity voi Maximum value of v so that particle does not exit the magnetic field region is X X X XX X x x 2a X X x x axx x XX X X X 4 qBoa 3 m qBoa m 5 gBa 4 m X X X

An assembly of charges q q q q are at positions x 1 m 2 m 4 m 8 m respectively from origin The electric potential due to these charges at origin is 9 680 9 6180 9 4180 9 2TEO

Total energy stored in the capacitor system shown in figur is 5 V 3 F 62 5 J 32 5 J 45 J 12 5 J 3 F HK 6 F

Q46 Four point charges 8 C 1 C 1 C and 8 C are fixed at the points 27 2 m 3 2 m 3 2 m and 27 2 m respectively on the y axis A particle of mass 6 x 10 4 kg and charge 0 1 C moves along the x direction Its speed at x is vo Find the least value of vo for which the particle will cross the origin Also find the kinetic energy of the parti cle at the origin Assume that space is gravity free 9 10 Nm C 2000 1 4TEO

The extremities of the solar diameter subtend a small angle 8 at any point on the earth Find the diameter of the image of the Sun formed by a concave mirror of focal length f distance the image of the Sun is formed in the focal plane

View in English Two blocks of mass 8 kg and 5 kg are connected by a heavy rope of mass 3 kg Complete system is accelerated upwards by 10 m s2 as shown in the figure The tension at the point P will be 1 3 80N 90N 160N 8kg P 5kg kg Ja 10 m s

sity of the Electric Field 24 A point charge 50 C is located in the x y plane at the position vector 21 3 m The electric field at the point of position vector r 81 5j m in vector from is equal to 1 90 31 41 V m 5 2 90 31 41 V m 3 900 31 41 V m 4 900 31 41 V m Two point charges and 30 are placed

In a constant magnetic field of 1 2 Tesla along the direction find the value of the path integral al in the units of Tesla m on a square loop of side length 1 2 meters The normal to the loop makes an angle of 60 to the z axis as shown in the figure 160

Please solve and explain how to find the direction of m etic field by right hand rule in each case 60 TU P Magnetic field due to a current element Magnetic field due to current carrying conductors Find the magnetic field at point P due to given arrangements of current carrying wire bva EXERCISE 4 1 Aakash Educational Services Limited Regd Office 0 C Uniform frame

6 Consider a spherical volume which has uniform charge density p from x R to x 2R There is no charge from x 0 to x R and from x 2R to inifinity The electric potential due to this charge A at x 0 is 0 B at x R is 3pR 2 2R R C at x 2R is 7pR 6 D at x 3R 2 is 8pR 36

In a circular wire of radius R a battery of voltage Vo is applied across point A and B If resistance of circular wire is 160 then 21 V B Current through battery is Current through battery is 2V0 7 Magnetic field at centre O due to current in circular wire is zero

2 11 A copper block of mass 2 5 kg is heated in a furnace to a temperature of 500 C and then placed on large ice block The maximum amount of ice that can melt is Specific heat of copper 0 39 Jg C latent heat of fusion of water 335 Jg 1 1 2 kg 2 1 455 kg 3 1 kg 4 2 5 kg

How do we know the relation between capacitors i e par allel series for combination of dielectrics capacitors Eg Here in this question why C2 and C3 are in series with themselves and parallel with C1 82 Ho 4 2 A 2 K 4 S d 2 4 2

A capacitor of capacitance C is connected across an ac source of voltage V given by V V sinot The displacement current between the plates of the capacitor would then be given by 1 I VowCsinot 2 Id VowCcost 3 4 Vo Id coswt C Id Vo sin

9 The effective resistance of a parallel connection that 25 consists of four wires of equal length equal area of cross section and same material is 0 25 0 What 25 will be the effective resistance if they are connected in series u 25 2 3 4 10 40 0 25 0 5 0 25 x 4 1 00 25 ft

A Decreases C Remains unchanged D First decreases and then increases A car is moving on a straight road due north with a uniform speed of 50 km h when it turns left through 90 If the speed remains unchanged after turning the change in the velocity of the car in the turning process is A Zero B 50 2 km h S W direction C 50 2 km h N W direction D 50 km h due west

Q21 The amount of heat energy required to change 1 Kg of a solid into liquid at its melting point is known as O Latent heat of vaporisation O Latent heat O Latent heat of fusion O none of these O Other

A thick current carrying cable of radius R carries current T uniformly distributed across its cross section The variation of magnetic field B r due to the cable with the distance r from the axis of the cable is represented by La B 2 B 3 B G B r1 r 120 015781 158 019 4036 10 21 0 80 To 21 0 5 6 9 ou l 69 0801 681 8 eho 9 E

In the diagram shown the sum of masses M and M2 is m Answer the following questions A B What can be the maximum possible acceleration of the masses A g 2 C 2g B g A mg 2 D None What can be the maximum value of the tension in the string joining the masses B mg C 2mg M D None M

The electron concentration in an n type semiconductor is the same as hole concentration in a p type semiconductor An external field electric is applied across each of them Compare the currents in them 1 4 current in n type current in p type No current will flow in p type current will only flow in n type current in n type current in p type current in p type current in n type

30 with the horizontal When where and g 9 8 m s 5 s after 127 5 m from foot of tower 42 74 m s at 53 24 with ho 5 A ball thrown horizontally with an initial velocity of 25 m s from a certain height falls to ground in 3s From what height was it thrown and what is its horizontal range g 9 8 m 44 1 m 75

Figure represents a square having charges q q q and q at its four corners as shown The electric potential will be zero at B 9 9 D E OA E and B only OA E and D only OB E and D only O All the points 4 C q