Basic Physics Questions and Answers

FICTIONAL TRAVEL Improvise the given product Assume how the product would be 10 years from now 2031 and list down the upgraded features Examples Mobile Watch

A physics professor built the circuit shown in the figure Assume the inductance is L 3 10 H the resistance is R 7 80 02 and the battery emf is E 36 0 S AVR EL R ww ele L AV a Find R when the current is 2 00 A EL b Calculate the emf in V across the inductor when the current is 4 50 A

Velocity at ground v u 2gH 1 Time taken to reach the ground H ut gt This is a quadratic equation that can be solved by factorisation or using quadratic formula to calculate time Let three balls 1 2 and 3 are allowed to fall under gravity from the same height Ball 1 is thrown vertically upward with speed u and it reaches the ground in time t Ball 2 is thrown vertically downward with the same 0 speed u and it reaches the ground in time t Ball 3 is dropped i e u from the same height and it reaches ground in time t Then the relationship between t t and t is given by Downward motion of object t Upward motion of sound t ALLEN H t3 t t An object is dropped in a well of depth d and the sound of splash in water is heard after a certain time T 2d g d 2 u 0 143 the equation to calculate time taken to re ch the ground why is initial velocity taken a

A vector A of magnitude 12 units makes angle 60 45 with x y axis respectively then the magnitude of it s z component is Figure shows a bar of mass m moving with a constant speed vo on horizontal surface around a semi circular fence of radius R The average normal force acting on the bar due to contact with the fence is

At the height 80 m an aeroplane is moving wi 150 m s Abomb is dropped from it so as to hi target At what distance from the target shou the bomb be dropped given g 10 m s 1 605 3 m 3 80 m 2 600 m 4 230 m

A simple pendulum has a time period T in vacuum time period when it is completely immersed in a liqu of density one nineth of the density of the material the bob is A T B T C T 3 T 8 D Clear Response

7 Both the blocks shown in figure have same mass m All the pulleys and strings are massless A Acceleration of block A is 2g 5 bol bol g B Acceleration of block A is 5 C Acceleration of block B is 5 m Block A m Block B 3mg D Tension in the string attached with block A is 5

Paragraph for Questions 3 and 4 Two bodies A and B of masses 10 kg and 5 kg are placed very slightly separated as shown in figure The coefficient of friction between the floor and the blocks is 0 4 Block A is pushed by an external force F The value of F can be changed It is known that when the welding between block A and ground breaks block A will start pressing block B and when welding of B also breaks block B will start pressing the vertical wall F A 10kg B 5kg What should be the minimum value of F in N so that block B can press the vertical wall If F 20 N with how much force in N does block A presses the block B

On a train moving along east with a constant speed v a boy revolves a bob with string of length c smooth surface of a train with equal constant speed v relative to train Mark the INCORRECT option s A Maximum speed of bob is 3 v in ground frame 4mv C B Tension in string connecting bob is at an instant my l D Minimum speed of bob is zero in ground frame C Tension in string is at all the moments V

Electrons go through a single slit 300 nm wide and strike a screen 25 0 cm away At angles of 20 0 from the center of the diffraction pattern no electrons hit the screen but electrons hit at all points closer to the center a electrons Sit b What will be the next pair of larger angles at which no electrons hit the screen

In the given figure both the blocks are in equilibrium and hanging vertically as shown When thread is cut which of the following statements give correct description immediately after the thread is cut Given g 10 m s A C Acceleration of 1 kg is 10 m s downward Acceleration of 2kg block is 5 m s upward heeeeee 2kg 1kg B Acceleration of 2kg is zero D Acceleration of 1kg is zero

9 A ball of mass m is rotating in a circle of radius r with speed v inside a smooth cone as shown in figure Let N be the normal reaction on the ball by the cone then choose the correct option A N mgcos0 C Ncos0 mv r 0 0 m B gcose v r D N mgsin sir sine

3 f the mass of block A is m in kg and acceleration of A block along the smooth inclined plane is m s2 up the inclined plane Than find the mass of block A in kg i 2 ulleys and strings are ideal as shown in figure 37 7 5 kg

1 Two bodies of mass 10 kg and 2 kg are moving with velocities 21 71 3k ms and 101 351 3k ms respectively The velocity of their centre of mass is a 2 ms c 2j 2k ms A b 2kms d 21 2 2k ms CUDA PRI

a Construct a sequence of continuous functions f defined on 0 1 such that fn z pointwise for all x 0 1 but fn 0 in the L sense b Let p x x for x If we approximate it by the function f x a cos x b sinr a2 cos 2r b2 sin 2r what choice of coefficients will minimize the L error

Figure shows a block kept on a rough inclined plane The maximum external force down the incline for which the block remains at rest is IN while the maximum external force up the incline for which the block is at rest is 7 N The coefficient of static friction u is A 3 B 1 16 30 C 3 D 4 3 3

A solenoid with a cross sectional area of 1 87x10 m is 0 745 m long and has 980 turns per meter Part A Find the induced emf in this solenoid if the current in it is increased from 0 to 2 50 A in 35 8 ms 1 A AEO

41 The ladder shown in Fig 8 E41 is 6 m long and is supported by a horizontal floor and vertical wall The coefficient of friction between the floor and the ladder is 0 4 and between wall and ladder is 0 25 The weight of ladder is 200 N and may be considered a concentrated at G The ladder also supports a vertical load of 900 N at C which is at a distance of 1 m from B Determine the least value of a at which the ladder may be placed without slipping Determine the reaction at that Ans N 1000 N F 400 N Ng 400 N Fg 100 N and a 61 927 3 m 6 m a 200 N Fig 8 E41 Im 900 N

A minimum horizontal force of 10 N is necessary to hold a block stationary against a wall The coefficient of friction between the block and the wall is 0 2 Contact force by the wall on the block is 0 2 A 10 N B 2 N 10N C 12 N D 2 26 N

A uniform rod falls without rotation onto a smooth horizontal plane Prove that the angular velocity of the rod after striking the table will be a maximum if the rod makes an angle with the horizontal before striking cos 3 amity of

Calculate the thermal energy lost in a collision if a 0 150 kg bullet travelling with a spee of 30 m s strikes and embeds in to a metal ball of mass 3 kg at rest Answer a 15 3 J b 90 3 J c 64 3 J d 38 6 J O attempting questi D

In 1924 the French physicist reasoned that nature was symmetrical and that the two basic physical entities matter and energy must have symmetrical character Read the following passage to answer the given questions based on it Choose the correct options Marks 1 If electron is placed in 50 V potential difference what is gain in kinetic energy OPTIONS 8 10 18 J 80 10 18 J 18 10 18 J 28 10 18 J

Three identical uniform rods are each acted on by two or more forces all perpendicular to the rods and all equal in magnitude Which of the rods could be in static equilibrium if an additional force is applied at the center of mass of the rod f 1 1 Only 1mo 2 3 2 Only 2 Only 1 and 2

A block of mass m is released from rest from the top of the wedge of mass 2m as shown in figure Friction is absent everywhere Then h 2m Smooth 30 Linear momentum of system is conserved in all directions Linear momentum of system is conserved in vertical direction Linear momentum of system is conserved in horizontal direction Mechanical energy of system is not conserved

A physical quantity X is given by X A C where A and C are measured independently A 10 0 1 in Sl units and C 5 0 1 in Sl un A 2C percentage uncertainty in X is a write value of 10a

A C A 2C measured A physical quantity X is given by X where A and C are independently A 10 0 1 in SI units and C 5 0 1 in Sl units If percentage uncertainty in X is a write value of 10a

1 Determine the moment of inertia and the radius of gyration of the composite section with respect to an axis which is parallel to the plate and passes through the centroid C of the section A 36 mm 42 mm 28 mm B

c The ladder shown in Fig 3 c is 6m long and is supported by a horizontal floor and vertical wall The coefficient of friction between the floor and the ladder is 0 4 and between wall and ladder is 0 25 The weight of ladder is 200 N and may be considered a concentrated at G The ladder also supports a vertical load of 900 N at C which is at a distance of 1 m from B Determine the least value of a at which the ladder may be placed without slipping Determine the reaction at that point 3 m w 9 200 N Fig 3 c m 900 N 11111

22 A ball falls freely from rest The ratio of the distances travelled in first second third and fourth second is 1 4 3 2 1 3 1 2 3 4 2 7 5 3 1 4 1 3 5 7

Which of the given pyramid can be spindle shaped Only One Correct Answer A If prepared for numbers for a tree having grazing food chain B C If prepared for number in parasitic food chain on a tree If prepared for biomass of a tree D If prepared for biomass in a grassland

Consider a system with n possible states One with energy 0 another with energy 0 and the others with energies are 2 3 n 1 a Calculate the average energy of the system b Find the limiting values when the temperature is i very high and ii low

4 m 37 S and S are two coherent sources of sound of frequency 110 Hz each They have no S initial phase difference The intensity at a point P due to S is I and due to S is 410 If the velocity of sound is 330 m s then the resultant intensity at P 3 m is a lo c 310 Th S b 910 d 810 90 P

wave starting from source S follows A E B two paths SEFD and S SEABFD If AB 1 AE BF 0 6 l and wavelength wave is 11 m If maximum sound is heard at D th minimum value of length is AN L F

At a point beats frequency of n Hz is observed It means a medium particles at that point are vibrating with frequency n Hz b amplitude of vibrations changes simple harmonically with frequency n Hz at that point only c at that zero intensity is observed 2n times per second d none of the above

A sound wave of wavelength 0 40 m enters the tube at S The smallest radius r of the circular segment to hear minimum at detector D must be a 1 75 m 0 175 m c 0 93 m d 9 3 m S D

oop in the Figure 2 14 Its length along the x direction is a and along the y direction is b Find the far field radiated by this loop in the xz and yz planes respectively Show that the far field is the same as that of a magnetic dipole provided that the dipole moment is given by kl jw IS with S ab Show all steps Answer below provided as a reference E j H E j j H j KKL e 4 r KKL jkr e 4 n r KKL e jhr 4 jka r jkr KKL e 4 n r sin y sin 00 sin Ox sin 00 Z

26 A tuning fork of frequency 380 Hz is moving towards a wall with a velocity of 4 m s Then the number of beats heard by a stationary listener between direct and reflected sounds will be velocity of sound in air is 340 m s 27 a 0 c 7 A 1 Y b 5 d 10 Wall

Parallel beam of light incident normally on a wall illuminates a round spot of radius 4 0 cm on it When a ball surface of which is mirrored is placed with its centre on the axis of the beam and at a distance of 11 cm from the wall a large part of the wall is illuminated but at the centre a circular shadow of radius 52 cm is formed Find radius of the ball

ou can paddle your cycle maximum three times per second If the diameter of driver paddle wheel is 20 cm and follower gear wheel is 8 cm what is the maximum speed in rpm that you can achieve b Considering a frictionless differential wheel and axle system find out how mechanical advantage is related to the diameters of wheel and axles c In case of a

ull of 7 6 A block of iron is kept at the bottom water at 2 C The water exerts bouyant force on the block If the temperature of water is increased by 1 C the temperature of iron block also increases by 1 C The bouyant force on the block by water A will increase B will decrease C will not change D may decrease or increase depending on the values of their coefficient of expansion

A solid cylinder of mass m and volume v is suspended from ceiling by a spring o spring constant k It has cross section area A It is submerged in a liquid of density upto half its length If a small block of mass Mo is kept at the centre of the top the amplitude of small oscillation will be 1 uestion Type Single Correct Type 2 3 Mog K Vpg Mog K Apg www Mo m g K Apg 00000

02 The linear mass density of a thin rigid rod of length 2m varies with distance x from one end of the rod at x 0 along the length as 3x kg m The moment of inertia of the rod about a perpendicular axis passing through the end of the rod at

Nuclei of a radioactive element X are being produced at constant rate K and this element decays to a stable nucleus Y with a decay constant A and half life T 2 At time t 0 there are No nuclei of the element X The number Ny of nucleus Y at time t is

27 Starting from rest a 10kg bowling all solid sphere rolls down a ramp The ramp has a height of 5 0m Calculate the speed of the ball at the bottom of the ramp a 6 84 m s b 10 3 m s c 8 37 m s d 9 91 m s

A narrow slit S transmitting light of wavelength A is placed a distance d above a large plane mirrors as shown in the figure The light coming directly form the slit and that coming after reflection from the plane mirror interfere on a screen 2 placed at a distance D from the slit Assume that the mirror is 100 reflecting Given D 1m d 0 5 mm and A 500 nm d 0 5mm k Find the fringe width in mm of the interference pattern formed on the screen D Im

Q 89 Find magnitude of charge which exerts a force of charge of 100 C when kept in air at a distance of 9 cm from it a 10 2 C b 10 3 C 10 C d 10 C Q90 Find the magnitude of electric force acting on an electron located in an electric field with an intensity of 5x10 N C Charge on electron 1 6 10 1 C a 16 10 N c8x10 16 N Q 91 Find intensity of electric field at a point 50 cm away from a charge of 25 mC in air a 8x10 N C C 6 5x108 N C a 2x10 J 1 56x10 3J b 1 6x10 19 N d 5x104N Q 92 Find the workdone when a charge of 50 C is moved from a point at a potential 10 V to a point at a potential of 30 V in an electric field b9x108 N C d 6 8x105 N C Q 93 Find electric potential if the workdone to move a charge of 100 C from one point to another is 5 J a 3 5x104 V b 5x105 V b b 2 5x10 J d 6 5x10 5 J 2 A 6x106V d 5x104 V Q 94 A current of 0 5 A is flowing through a bulb for 10 minutes Find the charge flowing through the circuit a 250 C b 300 C Non a C25 C d 30 C Q 95 A charge of 600 C is flowing through a circuit for 5 minutes Find the current in the circuit a 1 8 A 2 2 A d 2 25 A

Sound wave in form of sine wave is travelling along x axis AP x graph is shown Choose correct option AP JALA B Particle on just left side of A and just right side of A are moving in opposite directions Speed of particle on just left of A is less than that on right of A Particles on just left and just right of B have opposite direction of motion Particles on just left and just right of C are moving in same direction

tion 1 What is the minimum force that needs to be applied on a body of mass 100 g kept on a horizontal surface to set the body in motion Given coefficient of friction between the surfa

Consider a synthetic forward option with the strike price K 19 while the initial stock price So 20 This includes a purchase of put and selling call at time T 1 year Assume that S 18 Evaluate the payoff Find the profit

A concave lens and a convex lens of same focal length 10 cm are separated by 24 cm A point size object is placed in front of concave lens at 15 cm Distance between object and final image is O 10 15 cm 24 cm