Basic Physics Questions and Answers

4 A ball of mass m moving with a constant velocity strikes against a ball of same mass at rest If e is the coefficient of restitution then what will be the ratio of velocity of two balls after collision 1 e a b d c 1 e 1 e 1 e e 1 e 1 e 1 e 1

2x The position of a particle is given by r acos mt i asin at j btk where for one revolution of the particle following a helical path The distance moved by the particle in one full and T is time period T turn of the helix is A 6 CYTA b DA a b o B 25 6 22

The net impedance of the following circuit at very low frequencies of the source will be ooooo wwwwwwww 2 mH 402 292 6Q 20 40

27 A positively charged pendulum is oscillating in a uniform electric field pointing upwards Its time Si period as compared to that when it oscillates without electric field 1 Is less 2 Is more 3 Remains unchanged 4 Starts fluctuating 2

Example 50 The dispersive powers of crown and flint glasses are 0 03 and 0 05 respectively The refractive indiccs for yellow light for these glasses are 1 517 and 1 621 respectively It is desired to form an achromatic combination of prism of crown and flint glasses which can produce a deviation of 1 in the yellow ray Find the refracting angles of the two prisms needed

7 Aball is dropped on to a horizontal plate from a height h 9 m above it If the coefficient of restitution is e 1 2 the total distance travelled before the ball comes to rest is a 10 m b 15 m c 20 m d 25 m

14 A charged gold leaf electroscope has its leaves apart by certain amount having enclosed air When the electroscope is subjected to X rays then the leaves high 1 Further dilate 3 Collapse 2 Start oscillating 4 Remain unaltered

A bar magnet of magnetic moment 2Am is free to rotate about a vertical axis passing through its centre The magnet is released from rest from east west position Then the K E of the magnet as it takes north south position is B 25 T H 1 25 J 2 50 J 3 100 J 4 12 5

Five point charge each having magnitude q are placed at the corner of hexagon as shown in fig Net electric field at the centre O is E To get net electric field at O be to be 6E how much charge should be placed on sixth corner 9 9 1 6 q 3 5 q 6 O q q 2 6q 4 5 q

An object having its total mass concentrated at centre and having six identical rods of length leach attached to it symmetrically is placed on an inclined rough surface of inclination a Object looks like a wheel with six equally spaced spokes without rim Assume that there is no slipping and collision between the spokes and plane is perfectly inelastic and wheel always remains in the vertical plane Also assume object remains in contact with the plane and initially center of the object is at a distance I from the inclined plane and is released from rest The acceleration due to gravity is g Pick the CORRECT statement s for the motion of wheel long time after the motion has started 4 A Average speed of the centre of object attains a constant value B Mechanical energy of object remains conserved C Instantaneous power delivered by friction to the object is zero D The value of constant average speed of the centre of object attained is 8gl sin a 3

What would happen to an electron if it is released in a uniform electric field O Moves perpendicular to the field O Moves along the direction of the field O Moves opposite to the direction of the field O Remain stationary

3 F M m g M m smooth is n Numerical Value Type Questions The acceleration of the block B in the figure assuming the surfaces and the pulleys P and P are a IN F m M m n is 3F 17m 4F M m g M m 12317 Fe 2m OP B The acceleration of movable pulley P if acceleration of block A 1m s then is 18

47 r The magnetic induction at the centre of a 30 current carrying circular coil of radius 10 cm is 5 5 times the magnetic induction at a point on its axis The distance of the point from the centre of the coil in cm is 1 5 2 10 3 20 4 25 DER TEST SERIES JOINT PACKAGE COURSE 4x r 1 5 2 10 3 20 4 25 r 10 facturidisch dich useft as a soft 3727 at 4 fare ut a use a farg 0999DMD310320007

B 4 VA Vc If K is the dielectric constant of a medium and 38 permittivity of free space then the energy stored per unit volume of the medium is given by 1 K 2 KE 2 3 KEE 4 KEE 3 VA VB 4 VA Vc a nagai Kau faia acid 31 1 1 K E 2 KejE 3 KEE 4 KEE

One mole of ideal gas goes through process 2V 1 V when volume changes from V P A B D 4 5R 11 5R K 5 2R 2 K then change in temperature of the gas K K 1 m to 2 m is 3

The acceleration time graph of a particle moving in a straight line x axis is shown in figure If the initial velocity of particle is 20 m s in positive x direction then find the speed of particle at t 30 s in m s a m s 4 5 5 10 20 30 t s

The atomic masses of H and H are 2 0141 u and 4 0026 u respectively Taking the velocity of light in vacuum to be 2 998 108 m s 1 calculate the amount of energy in J liberated when two moles of H undergo a fusion to form one mole of H u 1 66057 10 27 kg A 2 3 10 2 J B C D 3 3 10 2 J 5 3 10 2 J 2 9 10 2 J

The amplitude of a simple pendulum is 10cm When the pendulum is at a displacement of 4cm from the mean position then what is the ratio of kinetic and potential energies at that point

An ideal transformer converts a 20 V primary input voltage to 100 V in secondary The current in secondary if the current in primary is 20 A is 4 A 20 A 0 3 A

In a meter bridge experiment resistances are connected as shown in figure The balancing length 1 55 cm Now an unknown resistance x is connected in series with P and the new balancing length is found to be 75 cm What is the value of The value of 11x in ohm Given P 4N A P 4 55cm E K 100 cm 1 2 Q C

When a battery of emf 8 V with internal resistance 0 5 2 is charged by a 120 V DC supply using a series resistance of 15 5 2 then what is the terminal voltage in volt of the battery

A long vertical wire carrying a current of 10 A in the upward direction is placed in a region where a horizontal magnetic field of magnitude 2 0 10 3 Texists from south to north Find the point where the resultant magnetic field is zero

A cabin is moved up the inclined plane with constant acceleration g sine A particle is projected with some velocity with respect to the cabin in a direction perpendicular to the inclined plane If maximum height attained by particle perpendicular to inclined plane is same as range of particle with respect to the cabin parallel to plane then calculate values of cot 0 0

3 2 7 A simple pendulum has a time period T when or the earth s surface and T when taken to a heigh 2R above the earth s surface where R is the radiu 2 of earth s surface The value of 1 610 sec 9 2 3 2 T 1 13 T 2 1 4 9 is

A 250 g air track glider is attached to a spring with spring constant 4 0 N m The damping constant due to air resistance is 0 015 kg s The glider is pulled out 20 cm from equilibrium and released How many oscillations will it make during the time in which the amplitude decays to e 1 of its initial value

6 A particle is moving simple harmonically 8 and x 4 Calculate two extreme positions x the phase difference between x 1 and x 4 T 1 6 TT 2 13t 6 None of these

Two particles A and B approach each other from very large distance as shown in the figure Their masses charges and speeds are mentioned in the figure Neglect gravitational force 2M 2Q 2V M Q V B A If the least separation between the particles is b the speed of M in center of mass frame when particles are closest is 2LV b B If the least separation between the particles is b the speed of M in center of mass frame when particles are closest is LV b C If the least separation between the particles is b the speed of 2M in center of mass frame when particles are closest is 2LV b D If the least separation between the particles is b the speed of 2M in center of mass frame when particles

A uniform rope of mass m hangs freely between two hooks in the same horizontal line as shown in the figure The tangent to the rope at the hooks makes an angle 0 with the horizontal The tension in the rope at its lowest point is A mg 2 B 0 mg 2 tan 0 C mg tan 0 D mg cos 0

Please explain on search 2 answe rs are given both are equally right in my opinion because 1 1st expla ins that P W t where W qAV 2 same P then W 1 2qV of Capac itor means Ui Uf AU Wcons Please try to ans my ques and cor rect me if I am wrong somewhere The voltage of clouds is 4 x 10 volt with respect to ground In a lightening strike lasting 100 ms a charge of 4 coulombs is delivered to the ground The power of lightening strike is 1 160 MW 2 80 MW 3 20 MW 4 500 KW Ans 2 4x4x10 6 Sol Work done QV x4x4x

A boat which has a speed of 10 Km hr in still water cross a river of width 500 meter along the shortes possible path in 10 minutes the velocity of the river water in kilometer per hour is A 16 Km hr B 71 Km hr C 91 Km hr D 101 Km hr

If there are two vectorsA and B such that A B i 2 k and A B 1 k then choose the correct options A the angle between A and B is 60 C B j k B A i j D the angle between A and B is 120

2 3 7k B i 2k and c 1 4 then the magnitude of A BxC is Two vectors have magnitudes 3 units and 4 units then the angle between vectors degrees magnitude of resultant is 1 unit is

In the Potentiometer Experiment can you measure the unknown voltage Vx if its value larger than the power supply Vo Select one O Yes but only if Vx 2Vo O Yes but only if Vx 3Vo O Yes always No it can not be measured

r er 29 Two uniformly charged no hemispherical sheels each having uniform charge yo and radius R form a complete sphere not stuck together and surround a concentric spherical conducting shell of radius R 2 If hemispherical parts are in equilibrium then minimum surface charge density of inner conducting shell is A 20 B 6 2 C 0 D 20 30 A point charge q is borught from infinity slowly so that heat developed in the shell is negligible and is placed at the centre of a conducting neutral spherical shell of inner radius a and outer radius b then work done by external agent is PIE 3 e Cons clien2 yioseqa on a lan leviste al 3V V pon A Q B b qa kq 2b C espiertove 1 kq kq 2b 2a D kq kq 2a 2b

Five long wires A B C D E each carrying current are placed on the vertices of a regular hexagon of side a as shown Each wire carries current out of plane of paper Resultant magnetic field at centre O is along OA OB OC

2 A projectile is moving at 20m s at its highest 21 point where it breaks into two equal parts due to an internal explosion One part moves vertically up at 30 m s with respect to ground Then the other part will move with speed 1 20 m s 2 10 13 m s 3 50 m s 4 30 m s a wall of mass 22 20 and 1 20 m s 3 50 m s for du for at arate aci fa 30 m s a fr ari 2 10 13 m s 4 30 m s 1

If the vectors P ai aj 3k and a 27 are perpendicular to each other then the positive value of a is A zero B 1 C 2 D 3 The x y z co ordinates of two points A and B are given respectively as 0 3 1 and 2 6 4 The displacement vector from A to B is given by A 2i 67 4k B 21 3 3k C 2i 3j 5k D 2 3j 5k

The angle between the two vector A 31 43 5k and B 3 4 5k is A 60 B 45 C 90 D 30 Maximum and minimum values of the resultant of two forces acting at a point are 7 N N respectively The smaller force will be equal to A 5 N B 4 N C 2 N D

ta 3 6 3 cm s 4 7 3 cm s A rod of length is pivoted at one of the ends 18 and is made to rotate in a horizontal plane as shown in figure with a constant angular speed A ball of mass m suspended by a string of length from the other end of the rod If the angle made by the string with the vertical is 0 then angular speed of rotation is 1 3 1 sin 0 g tan 0 1 sin 0 2 4 g cos 0 m g cot 0 1 cot 0 3 6 3 cm s and and fan far an guran and is ich after 1 4 7 3 cm s suffert fr er fedte and fit 3 0 1 sin 0 g tan 0 1 sin 0 2 bi at qua m cos 0 g cot 1 cot 0

33 The Stoke s theorem can be used to find which of the following O volume enclosed by a function in the given region Ocurf of the function REMAINING TI OArea enclosed Linear distanc

3 The angle between the two vectors 21 37 kandi 2 4k is A 90 B 0 C 180 D 45 If a vector 2 2j 3k and B 31 6 nk are perpendicular to each other then the value of n is A 4 B 12 C 6 D 6

Which of the following statements is are potentiometer circuit A Sensitive varies inversely the length of the potentiometer B Sensitivity is directly proportional to t potential difference applied across the potentiometer wire

A man is walking towards east at the rate of 2 km h The rain appears to him to come down vertically at the rate of 2 km h The actual velocity and direction of rainfall with the vertical respectively are O O O 2 2 kmh 45 15 kmh km h 30 2 km 0

The air bubble formed by explosion inside water performed oscillations with time period Tthat is directly proportional to pdE where p is pressure d is the density and E is the energy due to explosion The values of a b and c will be O 511 6 2 3 511 6 3 2 511 6 2 3

Primary batteries cannot be recharged and reused again Lead storage battery is an example of secondary battery O In a H O fuel cell water is electrolysed to give H2 and O2 O In a Ni Cd battery the specific gravity of the alkaline electrolyte remains same

REMAINING TIME HOURS MINUTES SECONDS 1 29 If the K E of an electron a proton a neutron and an a particle is identical the maximum de Broglie wavelength will be for On particle Electron O Proton ONeutron

Moment of inertia of a thin uniform rod rotatin about the perpendicular axis passing through it center is 1 If the same rod is bent into a ring an its moment of inertia about its diameter is the the ratio 1 8 0 22 is 2 5 112 2 4 4 2

A Carnot engine is working between temperature T source and T sink The efficiency is 40 If T 500 K then by how much amount T must be increased so that efficiently increases to 60 200 K 300 K 250 K 100 K

Two instruments A and B measure the length of wire as LA 1 00 m and LB 1 000 m then Both instruments are equally precise A is less precise than B A is more precise than B A has less percentage error

A It is easier to start a car engine on a warm day than on a chilly cold day because the internal resistance of battery decreases with rise in temperature B It is more economical to transmit electric power at high voltage and low current rather than at low voltage and high current because heat loss is proportional to square of current C The heating coil of an electric iron is enclosed in mica sheets because mica is a bad conductor of heat and good conductor of electricity D The heating coil of an electric iron is enclosed in mica sheets because mica is a good conductor of heat and bad conductor