Basic Physics Questions and Answers

Suppose the masses of two bodies are doubled and the distance between them is halved The gravitational force between them is a a the same as its original value b b times its original value c c 8 times its original value d d 16 times its original value d 16 times its original value d 16 times its original value

A proton accelerated by a potential difference moves through a a transverse magnetic field in a circular arc of radius 20 cm as shown in figure The angle 0 through which the proton deviates from the initial direction of its motion is 1 2 3 15 30 te Question Type Single Correct Type 45 X X X B X d 10cm

The elastic constant and density of sea water are respectively 4 312 10 N m and 2 2 10 kg m In a sonar experiment it was found that the acoustic echo from the sea bed is heard after 3 second The depth of the sea is 4 2 km 2 1 km 1 4 km 3 3 km

A graph between Velocity and displacement of a particle performing SHM is shown Find the acceleration when the particle is at half of maximum displacement from mean position 2 5 O O O v cm s 10 10 10 cm s 20 cm s 30 cm s 40 cm s 2 5 x cm

A 60 kg monkey climbs on a rope which can withstand a maximum tension of 900 N The case in which the rope will break if the monkey NCERT I XI Pg 113 1 Climbs up with acceleration of 6 m s 2 Climbs down with acceleration of 4 m s 3 Climbs up with uniform speed of 5 m s 4 Falls down the rope nearly freely under gravity

7 is moving in the positive direction of x axis At initial position x 0 its velocity is 1 ms 1 then its velocity at x 10 m is use the graph given Power W 4 2 O O O 10 m 4 ms 1 2 ms 1 3 2 ms 1 100 X

A charge Q is placed at the centre of an isolated metallic shell of inner radius a and outer radius b as shown in the figure Find out the correct statements out of the following statements If inner surface of the metallic sphere is earthed charge on inner surface is zero If outer surface of the metallic sphere is

Suppose you are driving north and suddenly hit your brakes to avoid a dog on the road As you come to a stop your acceleration is directed a a North b b South c c nowhere because acceleration is a scalar d d downwards

Suppose you go from the earth to a planet where the acceleration of gravity is 2 5 m s On the new planet your mass will be about a a the same b b times its value on Earth c c 2 times its value on Earth d d 4 times its value on Earth

by y 3 mm sin sin 400 t TX 15 Where x is the distance in cm measured from one end of the string t is the time in seconds and y gives the displacement The string vibrates in 4 loops The speed of transverse waves along the string equals for the fundamental mode O O 60 m s 120 m s string 30 m s 15 m s

When a ramp is used to lift a body up the uphill force required to push a body is a a less than the weight of the body b b more than the weight of the body c c equal to the weight of the body d d can t tell

and mass M is pivoted at the rim 27 A disc of and is set for small oscillations about an axis perpendicular to plane of disc If a simple pendulum has to have the same time period as that of the disc the length of the pendulum should be 5 R 2 b R J MR a c R M 13312 d R T 2 12 f recond s pendulum is decreased b

The figure shows a top view of a frictionless horizontal surface where there are two indentical springs with particles of mass m and m attached to them Each spring has a spring constant of 1200 N m The particles are pulled to the right and then released from the positions shown in the figure How much time passes before the particles are again side by side for the first time if m 3 0 kg and m 27 kg 10 m www m A B C I 40 20 3 sec sec sec D Natural length T sec

A siphon has a uniform circular diameter with its crest A 1 8 m above the water level of vessel B of large cross section then take g 10 m s and atmospheric pressure P 10 5 N m B O 1 8my 3 6m Velocity of flow through pipe is 6 2 m s Pressure at A is 0 52 x 105 N m Velocity of flow through pipe is 6 m s None of these cm

29 The ratio of the maximum wavelength of the Lyman series in hydrogen spectrum to the maximum wavelength in the Panchen series is 3 6 52 105 15 7 a b c d 7 108

When the balance point is obtained in the potentiometer a current is drawn from A both the cells and auxiliary battery B cell only C auxiliary battery only D neither cell nor guxiliary battery

23 In a sample of a radioactive substance what fraction of the initial number of nuclei will remain undecayed where T half life of radioactive T after a time t substance a 2 b 2 1 2 2 T 1 2 1 c 1 1 d 4 ai noitq0 and vino 10

18 The air tight and smooth pistons of a cylindrical vessel are connected with a string as shown Initially pressure and temperature of the gas are Po and To The atmospheric pressure is also Po At a later 3 time tension in the string is PA where A is the cross 8 sectional are of the cylinder At this time the temperature of the gas has become 3 1 To 8 11 3 1 To 2 To 4 13 To

5 A closed vessel contains 8 g of oxygen and 7 g of nitrogen The total pressure is 10 atm at a given temperature If now oxygen is absorbed by introducing a suitable absorbent the pressure of the remaining gas in atm will be 1 2 2 10 3 4 4 5 nt volume for the monatomic

52 An element A decays into an element C by a two step process 4 A B 2He and B 2e Then a A and C are isotopes c B and C are isotopes b A and Care isobars d A and B are isobars

A meter bridge set up as shown to determine end correction at A and B When a resistance of 150 is used in left gap and 200 in right gap then null point comes at a distance 42 cm from A When these resistances are interchanged null point comes at distance 57 cm from A Values of end correction at A and B are www 1 cm 2 2 cm O 2 cm 3 cm 3 cm 4 cm G www B

41 92U235 nucleus absorbs nucleus absorbs a slow neutron and undergoes fission into 54X139 and 38Sr94 nuclei The other particles produced in this fission process are a 1 and 1 a b 28 and 1 neutron 3 neutrons c 2 neutrons

c distance A ball is thrown vertically upward with a speed v height h metre above the ground The time taken for the ball to hit ground is 36 from F a c 1 1 v 2hg 2 b v 9 d 2hg v of a particle 9 2hg 1 1 along X axis at tim The displacement

3 If swimmer can swim at 5m sec in still water and velocity of flow is 3m sec then angle between direction of velocity of swimmer with respect to river and the direction of river flow if swimmer crosses the river in minimum time im nt 4 m ses and velocity of

3 2 Energy of all molecules of a monatomic gas having a volume V and pressure P is 3 2 PV The total translational kinetic energy of all molecules of a diatomic gas at the same volume and pressure is 1 1 2 PV 2 3 2 PV 4 3 PV 3 5 2 PV Cortain amount of an ideal gas is contained in a closed

Ao 16 The activity of a sample reduces from Ao to in one 3 hour The activity after 3 hours more will be Ao a c A 3 3 b Ab 9 Ao 9 3 d 27

6 The most appropriate SI unit for measuring the length of an automobile is the a meter b kilogram c second d liter 7 The symbol mm represents a a micrometer b megameter c millimeter d manometer 8 The SI base unit used to measure mass is the a meter b kilogram c second d liter 9 The SI base unit for time is a 1 day b 1 minute c 1 hour d 1 second

a a Newton s first law b b Newton s second law c c Newton s third law d d Law of inertia DI 361311 1131 prostering online i

aga a far Sync 08 19213E01040 Question Hindi The torque of a 3 phase induction motor is proportional to Option 1 Half of supply voltage Option 2 Square of the supply voltage Option 3 Supply voltage Option 4 Square root of supply voltage

33 The probability of survival of a radioactive nucleus for one mean life is 1 ay b 1 e The activity of a radioactive substance is R at time t c In 2 e d 1 In 2 e

A bullet is fired on a tree with a velocity of 200 m s If the bullet stops at a depth of 0 2 m inside the tree find the acceleration produced by the tree on the bullet Type the Solution in the space below r BI EE EE

Given L 4 H R 28 Q and C 400 F in the given circuit the resonance angular frequency in rad s is R L 4 H R 28C 40 716 Kufu qA rd s R www L mmmm HIC

6 The specific heat at constant volume for the monatomic argon is 0 075 kcal kg K whereas its gram molecular specific heat is C 2 98 cal mol K The mass of the argon atom is Avogadro s number 6 02 x 10 molecules mol 23

Two particles P and R have m 40 gm each and charge of equal magnitude Q but of opposite sign P is suspended from the ceiling by means of a massless string of length L When P and R are separated by a horizontal distance of 0 3 m P is in static equilibrium with the string making an angle of 45 with the vertical Taking the acceleration due to gravity to be 10 m s The magnitude of the charge Qis A 2 C B 4 C C 6 C D 10 C 1 45 P R

A circular coil having mass m is kept above ground x z plane at some height The coil carries a current i in the the direction shown in fig In which direction a uniform magnetic field B be applied so that the magnetic force balances the weight of the coil y Question Type Single Correct Type Z 1 Positive x direction 2 3 Negative x direction Positive z direction

a optics b thermodynamics c vibrations and wave phenomena d relativity 3 A baker makes a loaf of bread Identify the area of physics that this involves a optics c mechanics b thermodynamics d Relativity 4 According to the scientific method why does a physicist make observations and collect data a to decide which parts of a problem are important b to ask a question c to make an interpretation d to solve all problems 5 In the steps of the scientific method what is the next step after formulating and objectively testing hypotheses a interpreting results b stating conclusions c conducting experiments d making observations and collecting data

a If w and we are the half power frequencies and wo is the resonant frequency of a forced system show that w w w Works out the theor of M a and rove that diva

diagram Which of the following curves represents the same process 1 3 P 0 D P A B B T B 2 4 D P P V A D A D B T B

cm of potentiometer wire balance the e m fc a cell and 75 cm wire required for balance the terminal voltage of the cell when it is shunted by 6 2 resistor The internal resistance of the cell is 2 4 2 3 Zero

Mass is of 2 types rest mass and relativisti c mass Relativistic mass is caused due to momentum Light have momentum becaus e it exerts force So light have relativistic m ass and no rest mass Mathematically or ex perimentally prove that light have no rest m ass

10 15 A trolley is accelerating down an incline of angle 8 with acceleration g sin 8 A string with mass m hinged from top of the trolley Which of the following is correct a is the constant angle made by th string with vertical sine O a 0 a 0 Tension in the string T mg

QNo 127 Mark for review If a force acting on an object of mass 12 kg produces an acceleration of 5 m s then the same force applied to an object of mass 10 kg will produce an m s acceleration of 8 6 5

A rod of length L is hinged from one end It is brought to a horizontal position and released The angular velocity of the rod when it is in vertical position is 1 2g VL 2 3g VL

3 A transparent solid sphere of radius 2 cm and density p floats in a transparent liquid of density 2p kept in a beaker The bottom of the beaker is spherical in shape with radius of curvature 8 cm and is silvered to make it concave mirror as shown in the figure When an object is placed at a distance of 10 cm directly above the centre of the sphere its final image coincides with it Find h as shown in the figure the height of the liquid surface in the beaker from the apex of the bottom Consider the paraxial rays only The refractive index of the sphere is 3 2 and that of the liquid is 4 3 2 cm 10 cm

to M d R O M a 2M An Atwood machine consists of a fixed pulley wheel of radius R and uniform mass M a disk around which an effectively massless string passes connecting two blocks of mass M and 2M The lighter block is initially positioned a distance d above the ground The heavier block sits on an inclined plane with opening angle a There is a coefficient of friction between the surfaces of this block and the inclined plane Constant gravitational force acts downwards and assume that the string never slips a 5 pts Determine two conditions on the angle a which allow the lighter block

greater is the resistance of ammeter Reason R To decrease the range of ammeter additional shunt needs to be used across it 1 Point O a Both A and Ra correct explanatio b Both A and Ra the correct explar O c A is true but R is false PT d A is false and R is also false

During reflection of sound waves from denser medium A O both particle velocity and wave velocity get reversed B O only particle velocity get reversed C O only wave velocity get reversed D O both particle velocity and wave velocity does not reversed

1 Two particles each of mass m are moving in a circle of radius r with speed v each around the third mass M as shown in figure The value of v is 1 v 3 v G r m V M m 4 G M r4 m M m 2 v 4 V G r 4G r M m 4 M m

1 The motion of electrons between two successive collisions with the atoms ions in the presence of electric field follows a Straight line path b Circular path c Elliptical path d Curved path 2 The drift velocity of the electrons depends on a Dimensions of the conductor b Number density of free electrons in the conductor c Both a and b

Two uniform solid spheres made of copper have radii 15 cm and 20 cm respectively Both of them are heated to a temperature of 70 C and then placed in a region of ambient temperature equal to 45 C What will be the ratio of the initial rates of cooling of both the spheres