Basic Physics Questions and Answers

1 Two resistances are connected in two gaps of Meter Bridge The balance 1 point is 20 cm from the zero end A resistance of 15 ohm is connected in series with the smaller of the two The null point shifts to 40 cm What is the value of the bigger resistance a 9 ohm b 18 ohm c 27 ohm d 36 ohm

38 Given below are two statements labelled as Assertion A and Reason R Assertion A The current density is a vector quantity Reason R Current density has magnitude current per unit area and is directed along the direction of current Select the most appropriate answer from the options given below 1 Point Both A and R are true and R is the correct explanation of A Both A and R are true but R is not the correct explanation of A OA is true but R is false

Soft water is define as CO1 O The water which contains oxygen The water which contains anions of Br 1 S 2 O O O The water which does not contains the salts of Ca 2 Mg 2 The water which contains the salts of Ca 2 Mg 2

1 point 7 Which one of the following is a disadvantage of a potentiometer over a voltmeter Oa it can measure the e m f of a cell Ob it is heavy and not portable O c it can measure accurately very small potential difference of the order of few micro volt Od it can measure the internal resistance of a cell

3 3 3 F 4 5 F In fig given C 3 F C SuF C 9 F and 13 C 13uF What is the potential difference between points A and B OF 3 0 V 4 II V 22V 1 13 V 2 9 V A B 3 3 F 4 5 F faff C 3 F C 5 F C 9 F a C 13 F fak Saisy 22V 1 13 V 2 9V 3 0V A B 4 11 V

8 With a certain cell the balance point is obtained at 65 cm from the zero 1 point end of a potentiometer wire With another cell whose e m f is less than that of the first by 0 1 V the balance point is obtained at 60 cm What is the e m f of the first cell Oa 1 0 V Ob 1 2 V Oc 1 3 V Od 1 5 V

Anuncharged capacitor of capacitance 10 uF and a coil of inductance 2 mH are placed in series with a battery of emf 60 V The switch is closed Then the maximum energy stored in the capacitor is mJ

8 37 A bird is sitting in a wire cage hanging from the spring balance Let the reading of the spring balance be W If the bird flies about inside the cage the reading of the spring balance is W Which of the following is true T Mg 1 W W 2 2 W W 2 3 W W 2 R Me M My 80

Find the electric potential of the four charges at the center of the square with q 1 0 x 10 6 C and a 1 m as shown in the diagram 2q a 39 O 5 10 x 10 4 V O 4 30 x 10 4 V O 1 40 x 10 4 V 2 10 x 10 4 V 0 48 m 9 24

of the sur or a lens of roca length 10cm is silvered as shown in figure Radius of curvature of silvered surface is 10cm At a given instant if speed of object is m sec then the speed of image at that instant is a m s What will be the value of a f 10cm 1m sec 14 Object 10 3 cm 1m sec

One mole of an ideal gas having initial volume V pressure 2P and temperature T undergoes a cyclic process ABCDA as shown below The net work done in complete cycle is Pressure A P 1 T D A T B 2T Temp 2 2 RT 3 RT In 2 4 RT In 2

1 A 25KVA single phase transformer has 500 turns on the primary and 50 turns on the secondary winding The primary is connected to a 2500V 50Hz AC supply The flux density is 22 5T Determine a Secondary voltage and current on open circuit b Current flowing through the two windings on full load c Maximum value of flux and area of cross section of core

in reality I am rest outside an I am inertial frame of reference I get a valid equation but when acclerated person saw me he saw I am non innertial frame so he get another equation both two equation are not equal then the person has to go through the rest or get out of the car to get a valid equal equation otherwise the results of Newton s law is invalid by acclerated person Am I right

ss and radius of the Earth are 6 0 x 1024 kg and 6 4 x 106 m respectively The accelerat ced in the body of mass 1 kg and acceleration produced in the Earth are 9 8 m s and 1 m s a respectively C 1 63 x 10 24 m s and 9 8 m s respectively b d 9 8 m s and 1 63 x 1024 m s respectively 9 8 m s for both

Q A roller of weight W 4450 N rests on a smooth inclined plane and is kept from rolling down by a string as shown in the figure Find the tension S in the string and the reaction R at the point of contact B W 15 45

compound microscope has angular magnification equal to 100 If the object subtends an angle of 0 06 to the eye then then angle subtended by the image to the eye will be O 6 O60 O 0 06 O 0 2

Select true statement for repeater A repeater is a regenerator not an amplifier A A repeater has a table used in filtering decisions Repeaters can operate in physical link as well as data link layer Repeater connects segments of WAN

Q3 A wire with circular cross section is melt and again streched into a wire with square cross section of sar length New ressistance of wire compared to old will be a Increased c Remain same b Decreased d Insufficent date ff Junction rule is based on

What is the purpose of gateway O None of the mentioned purpose gateways are used O The forwarding of the data packet is done from one router to the other which basically forms a network 4 The main function of a gateway is to translate one protocol to the other O Determines the destination or the target IP address of the packet

The radius of a charged conducting sphere P is half that of a conducting sphere Q They are connected by a conducting wire The ratio of the electric field on the surface of P to that on the surface of Qis A 1 2 B 2 1 C 1 2 D 5 1

4 balance cannot be obtained The length of a potentiometer wire is A cell of 38 emf E is balanced at a length 1 3 from the positive end of the wire If the length of the wire is increased by E 2 At what distance will the same cell give a balance point 20 0 2 3 3 In the metre hridge experiment resistances are 39 4 Wal gafavaut are f 3E gford at an and at eft 1 20 2 fagd als de ch afe are 1 2 tea fer sa tigan atas fa 40 3 g gay face and 3

The advantage of circuit switching is More bandwidth is required in setting up dedicated channels O It can be used to transmit any other data even if the channel is free as the connection is dedicated to circuit switching O It takes a short time to establish a connection O It is a committed transmission channel is established between the computers which give a guaranteed data rate

A copper wire is length and radius r is nickel plated till its final radius is R and length 1 If the specific resistance of nickel and copper be K and K then the conductance of the nickel copper wire is z R r IK IK B IK A IK 7 K D T R

A conducting rod of length is rotating with angular velocity w about axi through end O and perpendicular to the rod A uniform magnetic field Bo exists out of the plane of the paper The potential difference Vp Vo will be 09 E 3 4B 00 9 4B 00 9 2B 0 9 2B 00 9

Mark the responsibility of network Layer You can select multiple correct answers Responsible for the source to destination delivery of individual packet from source host to the destination host Responsible for moving frames from one hop to the next Responsible for route or switch the packets to the final destination Responsible for the delivery of a message from one process to another

Identify the correct statements about Routers You can select multiple correc answers Router is internetworking device and internet uses routers to connect LANs and WANS Router is three layer device that routes packets based on switching table Router makes routing tables are normally dynamic and are updated using routing protocols Routers are based on their physical addresses for host to host delivery

Performance of a network is depends on OI O port connected to network Reliability and security O number of users types of transmission medium capabilities of the connect hardware Dedicated links carries traffic only

A ball is dropped from an upper floor some unknown distance above Tom s apartment As he looks out of his window which is 1 90 m tall Tom observes that it takes the ball 0 140 s to traverse the length of the window Determine how high h above the top of Tom s window the ball was dropped Ignore the effects of air resistance

A coin is released inside a lift at a height of m from the floor of the lift The height of th lift is 10 m The lift is moving with a acceleration of 9 m s downwards The tim after which the coin will strike with the floor lift is g 10 m s A 4s 4 C S 21 B 2s D 2 11 S

An object and a screen are kept at a distance 120 cm A lens of focal length 22 5 cm is ke between them so that a real image is formed the screen Find the possible location s of t lens A 90cm from object B 30cm from object C 40cm from object D 80cm from object

A particle has a rectilinear motion and the figure gives its displacement as a function of time Which of the following statements are true with respect to the motion B C X D A B in the motion between O and A the A velocity is positive and acceleration is negative C A between A and B the velocity and acceleration are positive t between B and C the velocity is negative and acceleration is positive between C and D the acceleration is positive

10 Q2 A planet of radius R radius of Earth has the same mass density as Earth Scientists dig well of depth on it and lower a wire of the same length and of linear mass density 10 3 kg m into it If the wire is not touching anywhere the force applied at the top of the wire by a person holding it in place is take the radius of Earth 6 x 106 m and the acceleration due to gravity on Earth 10 m s 2014 A 96 N B 108 N C 120 N D 150 N

A Electromagnetic force Gravitational force C Strong nuclear force Gravitational force Which pair does not have equal dimensions A Torque and Energy B Strong nuclear force Weak nuclea D Strong nuclear force Electromagn B Force and impulse D Elastic modulus and pressure C Angular momentum and planck s constant The surface area of a solid sphere of radius 3 cm is mm

block of mass M is placed on the top of bigger block of mass 10 M as shown in gure All the surfaces are frictionless The system is released from rest then ne distance moved by the bigger block t the instant the smaller block reaches the ground a 0 22 m c zero b 0 20 m d 0 24 m 10M 2 2m

3 A tuning fork with frequency 800 Hz produces resonance in a resonance column tube with upper end open and lower end closed by water surface Successive resonance are observed at length 9 75 cm 31 25 cm and 52 75 cm The speed of sound in air is a 500 m s b 156 m s c 344 m s d 172 m s Odisha NEET 2019 4 A tuning fork is used to produce resonance in a glass tube The length of the air column in this tube can be adjusted by a variable piston At room temperature of 27 C two successive resonances are produced at 20 cm and 73 cm of column length If the frequency of the tuning fork is 320 Hz the velocity of sound in air at 27 C is a 330 m s c 350 m s b 339 m s d 300 m s NEET 2018

b Fig 3 1 shows a boat that has been lifted out of a river The boat is suspended by two ropes It is stationary Tif ii C the tension Fig 3 1 not to scale The weight of the boat acting at the centre of mass is 24 kN The tensions in the ropes are T and T Determine iii the tension To 1 20m 0 40m 24 KN i the moment of the weight of the boat about the point P P moment T 13

10 A book has a mass of 400 g The surface of the book in contact with a table has dimensions 0 10 m 0 20 m The gravitational field strength g is 10 N kg What is the pressure exerted on the table due to the book A 0 08 N m B 8 0 N m C 20 N m D 200 N m

3 18 sec 4 9 sec A coin is released inside a lift at a height of 2 m 20 from the floor of the lift The height of the lift is 10 m The lift is moving with an acceleration of 9 m s downwards The time after which the coin will strike with the floor of lift is g 10 m s 2 2 s VIT A swimmer can swim in still water with speed v 21 2 18 sec 2 m fi SE E 10 m 1 1979 m s a di i anhgia af 4 g 10 m s e au fost r 4 9 sec V 2 2 s S

9 28 4 0 1A The equivalent resistance between A and B is 1 4R AO Bo The potent 2R2R 2 2R 3 R 2R 4 0 5R 28 3 0 25 f Afri NO BO wwwwww U SUPPR 4 0 1 ofbrat 2R2R 1 4R 2 2R 3 R 2R 4 0 5R

ALLEN A boy is running on a levelled road with velocity V 22 with a long hollow tube in his hand Water is falling vertically downwards with velocity u At what angle to the vertical should he incline the tube so that the water drops enters without touching its side 1 tan 3 tan 1 2 sin 4 cos van artister V and hea fter fond ge e a fan gach 2 sin 4

If x and y denote the distances of the object and image from the focus of a concave mirror The line y 4x cuts the graph at a point whose abscissa is 20 cm The focal length of the mirror is 120 cm Question Type Single Correct Type 2 40 cm y 3 30 cm X

Q 14 A positively charged sphere A is brought close without touching to a neutral sphere B Sphere B is touched with a grounded wire What is the charge on sphere B after the wire is removed A a positive b Negative c It stays neutral B d It depends on the contact time 1 poir

Q285 A screen is placed 90 cm from an object The image of the object on the screen is formed by a convex lens at two different locations separated by 20 cm The focal length of the lens is 1 18 81 cm 2 20 04 cm 3 13 01 cm 4 21 39 cm 1 2 3 4 We see that your answer is incorrect Please

A crane is used to lift loads vertically The output power of the crane to lift a car is P The crane then lifts a lorry which has 3 0 times the weight of the car through 0 25 of the distance in 0 50 of the time What is the output power of the crane now 3P 3P A D A B 00 C 8P D 6P

Displacement of a particle at time t is expressed as s 1 31 Now the acceleration of the particle at the time when the velocity vanishes 2 is Answer 0 0 00 01 02 02 0 3 03 04 04 05 05 06 06 07 07 08 08 09 09

A student suggests that there are several ways of transferring energy to a small stationary block of iron on a smooth table He makes the following suggestions 1 A 3 Heat it Shine light on it Pass a current through it Which suggestions are correct 1 and 2 only B 1 and 3 only C 2 and 3 only D 1 2 and 3

38 Two trains are approaching each other on parallel tracks with same velocity The whistle sound produced by one train is heard by a passenger in another train If actual frequency of whistle is 620Hz and apparent increase in its frequency is 100Hz the velocity of one of the two trains is Velocity of sound in air 335 ms 1 90kmph 2 72 kmph 3 54kmph 4 36 kmph

Two planets A and B have same mass and radii R The variation of density of the planets with distance from centre is shown in the following diagrams The ratio of acceleration due to gravity at the surface of the planets A and B will be P 1 1 Question Type Single Correct Type 2 1 R 3 1 R

13 Very small pollen grains are suspended in water A bright light shines from the side When looked at through a microscope small specks of light are seen to be moving in a rando jerky manner pollen grains in water eye microscope What are the moving specks of light pollen grains being hit by other pollen grains pollen grains being hit by water molecules bright light A B C water molecules being hit by other water molecules D water molecules being hit by pollen grains

In the following circuit the resistance of a 31 voltmeter is 10 0002 and that of an ammeter is 2002 If the reading of ammeter is 0 1A and that of voltmeter is 16 volt then the value of R is 1 1200 3 1180 4 12 4802 R ww 2 1000 4 1400 3 6 240 4 12 480 A fangen af 10 0000 2002 0 1 ofrer den alcenter a 48415 16 alez R 1 R www 1 1200 3 118Q 2 100 0 4 1400