Basic Physics Questions and Answers

4 4 First increases becomes maximum and then Three identical charges are placed at the corners of an equilateral triangle If the force between an charges is F then the net force on each will be 1 2 F 2 2F 3 3 F 4 3F

Three metal rods made of copper aluminium and brass each 20 cm long and 4 cm in diameter are placed end to en with aluminium between the other two The free ends of copper and brass are maintained at 100 and 0 C respectivel Assume that the thermal conductivity of copper is twice that of aluminium and four times that of brass The equilibrium temperatures of the copper aluminium and aluminium brass junctions are respectively 1 68 C and 75 C 2 75 C and 68 C 3 57 C and 86 C 4 86 C and 57 C

Black body spectrum is 1 Continuous spectrum with black lines 3 Continuous spectrum 4 None of the above 6 a despert 2 Continuous spectrum with black band

If Cp and Cy denoted the specific heat of unit gram mass of nitrogen at constant pressure and volume respectively then R is universal gas constant O Cp Cy R O Cp Cy 7R 28 Cp Cv R Cp Cy 28R

A cyclic process for one mole of an ideal gas is shown in the V T diagram The work done by the gas in AB BC and CA respectively are V Zero RT In O RT In V V RT B A RT RT In VR1 V V Zero T R T1 T RT V V Zero 16

Out of six particles two particles have speed of 3 units and other two particles have speed of 5 units The remaining two particles have speed of 2 units and 6 units The r m s speed of the gas molecule is nearly 1 4 units 2 4 24 units 3 9 6 units 4 4 30 units

One end of a metal rod of length 1 0m and area of cross section 100 cm is maintained at 100 C If the other end of the rod is maintained at 0 C the quantity of heat transmitted through the rod per minute will be coefficient of thermal conductivity of materal of rod 100W Kg K 1 3 x 10 J 2 6 x 10 J 3 9 x 10 J 4 12 x 10 J T AT R NORA

A box of negligible mass containing n moles of an ideal gas of molar mass M and adiabatic exponent Y moves with constant speed v on a smooth horizont surface If box suddenly stops then change in temperature of gas will be 7 1 Mv 4R O Y 1 Mv 8R O 7 1 Mv 2R Mv 2 y 1 R

A 3 ha field was plowed using a 15 cm wide animal drawn plow at 4 kph and fie efficiency of 75 The draft required to pull the plow is 60 kg Find the distance traveled to plow the field a C 66 67 km 200 km b d 133 33 266 67 km

In a double slit experiment light of wavelength 750 nm and 900 nm illuminates the slits with a slit separation of 2 mm forming two fringe patterns The distance of the screen from the slits is 2 m At what distance from the central maximum on the screen will a bright fringe from one pattern coincide with the bright fringe from the other pattern A 1 5 mm B 3 75 mm C 4 5 mm D 6 0 mm

A conversing beam of rays is incident on a diverging lens Having passed though the lens the rays intersect at a por 15 cm from the lens on the opposite side If the lens is removed the point where the rays meets will move 5 cm clos to the lens The focal length of the lens is CAIPMT 20 1 10 cm 2 20 cm 3 30 cm 4 5 cm

The magnetic field of Earth at the equator is approximately 40 x 10 Tesla If the Earth s magnetic field is due to a magnetic dipole at the centre of the Earth radius R 6400 km then the strength of the dipole is A 1023 Am B 102 Am C 10 Am D 1018 Am

A thin dielectric charged layer is placed in uniform electric field After placing it in field field on both side of dielectric is given by diagram If E 20 N C then component of applied field in N C along x axis is 60 E 30 E X

11 A rectangular block of mass M area of cross section A and density D is floating on surface of water If it is given a small vertical displacement in downward direction then the period of oscillation of the mass is 1 2 DL Apag 2 2mL D P B 3 2m V Dg 4 2 DL Pub

5 An a c reaches a maximum value of 100 ampere the frequency being 50 Hz Determine the rate of charge of the current in ampere per second when the time is a Ans a 27240 A S b 31420 A S c 0 0 00166 S b 0 01 S c 0 015 S

For a situation shown in figure find the refractive index of glass so that it will suffer total internal reflection at the vertical surface AIIMS 2016 60 3 1 31 4 1 6

A point source of sound is placed in a non absorbing medium Two points A and B are at the distance of 2 m and 3 m from the source The ratio of intensity of sound at point A and B respectively is 49 WIN LSIN 31

2 2 3 I 4 In a diffraction pattern due to a single slit of width a the first minimum is observed at an angle 30 when light wavelength 5000A is incident on the slit The first secondary maximum is observed at an angle of NEET I 201 1 7 4 4

hs of focal length 0 33m 4 None of the above The focal length of a plano concave lens is 10 cm then its focal length when its plane surface is polished is n 3 1 20 cm 4 none of these 2 5 cm 3 5 cm A combination of two thin lenses with focal lengths f and f respectively forms an image of distant object at dis

Tength of eyepiece Resolving power of a microscope depends upon 1 the focal length and aperture of the eye lens 2 the focal lengths of the objective and the eye 3 the apertures of the objective and the eye lens 4 the wavelength of light illuminating the object lens 4 great

The rms speed of a large number of molecules of a gas in a vessel is 600 m s If 25 of the gas leaks out at constant temperature then rms speed of the remaining molecules will be O 450 m s 1 800 m s 1 O 300 m s O 600 m s

A person can see clearly only upto a distance of 25cm He wants to read a book placed at a distance of 50cm Wha kind of lens does he required for his spectacles and what must be its power 1 concave 1 0 D 3 Concave 2 0 D 2 Convex 1 5 D 4 Convex 2 0 D for sighted ll hole 3 4 mm in oot

4 b and c both A person cannot see distinctly at the distance less than one metre Calculate the power of the lens that he should use to read a book at a distance of 25 cm 1 3 0 D 2 0 125D 3 3 0 D 4 4 0 D

A racing car moving towards a hill sounds its horn Driver of the car observes that the sound reflected from the hill has a pitch one octave higher than the actual sound of the horn If sound is travelling with velocity Vo then the car is moving with velocity 2

A particle perform SHM of amplitude A along a straight 3A from its mean 2 position Its kinetic energy gets increased by an amount mo A due to an impulsive force The new amplitude of the particle becomes line When it is at a distance of O 2A OPA O A L 24

A lens is placed between a source of light and a wall It forms images of area A and A on the wall for its two different postions The area of the sourece of light is 1 A A 2 AJ 2 A A 3 A A 4 A A 2

1 3 50 2 6 25 3 0 03 4 none of these All the listed things below are made of flint glass Which one of these have greatest dispersive power 1 prism 4 all have same w 2 glass slab 3 biconvex lens uplongth 4000 is incident at small angle on a prism of apex angle 4 The prism has n 1

Q10 a State the D Alemberts principle b A plane has a takeoff speed of 88 3 m s and requires 1365 m to reach that speed Determine the acceleration of the plane and the time required to reach that speed 2 3 5M

1 prism 2 glass slab 3 biconvex lens Light of wavelength 4000 is incident at small angle on a prism of apex angle 4 The prism has n 1 5 n 1 48 The angle of dispersion produced by the prism in this light is 1 0 2 2 0 08 0 192 3 4 None of these no goto cpectrum on the other side of the prism In the emergen

A mass m moves with a velocity y and collides inelastically with another identical mass at rest After collision the in a direction perpendicular to the initial direction of motion Find the speed of the AIEEE 2005 Ist mass moves with velocity 2nd mass after collision Dy 2 3v 2 3 4 3

1 Plane mirror The focal length of a concave mirror is f and the distance from the object to the principle focus is x The ratio of the size of the image to the size of the object is f x 1 5 3 X 2 3 4

STATEMENT 1 Two particles moving in the same direction do not lose all their energy in a completely inelastic AIEEE 2010 collision STATEMENT 2 Principle of conservation of momentum holds true for all kinds of collisions 1 Statement 1 is true Statement 2 is true Statement 2 is the correct explanation of Statement 1 2 Statement 1 is true Statement 2 is true Statement 2 is not the correct explanation of Statement 1 3 Statement 1 is false Statement 2 is true 4 Statement 1 is true Statement 2 is false

1 Violet ray 2 Green ray 4 Yellow ray 3 Red ray A spectrum is formed by a prism of dispersive power If the angle of deviation is s then the angular dispers is 1 o 8 2 8 3 1 08 4 wo When white light passes through the achromatic combination of prisms then what is observed

There is a small black dot at the centre C of a solid glass sphere of refractive index u When seen from outside will appear to be located 1 away from C for all values of u 2 at C for all values of u 3 at C for u 1 5 but away from C for p 1 5 4 at C only for 2 sps1 5 formed at

3 A prism having an apex angle of 40 and refractive index of 1 50 is located in front of a vertical plane mirror as shown A horizontal ray of light is incident on the prism The total angle through which the ray is deviated is 1 4 clockwise 2 178 clockwise M 3 2 clockwise 4 8 clockwise

The reason for shining of air bubble in water is 1 Diffraction of light 3 Scattering of light 2 Dispersion of light 4 Total internal reflection of light

1 60 2 100 3 180 4 240 When a plane mirror is placed horizontally on a level ground at a distance of 60m from the foot of a tower the to the tower and its image in the mirror subtend an angle of 90 at the eye The height of the tower will be 1 3 2 60 m 3 90 m 4 120 m An chinnt in at a distance of 05 m in front of a plane mirror Distance between the chient and image is

Two mirrors are inclined at an angle 9 as shown in the figure Light ray is incident parallel to one of the mirrors Light will start retracing its path after third reflection if

3 0 3 ms and 0 5 ms A moving block having mass m collides with another stationary block having mass 4m The lighter block comes to rest after collision When the initial velocity of the lighter block is v then the value of coefficient of restitution e will be NEET 2018 1 0 5 2 0 25 3 0 8 4 0 4 allide with another body B of mass 2m at rest The collision is head om

1 30 2 45 3 60 A parallel beam of monochromatic light is incident at one surface of a equilateral prism Angle of incidence is 55 an angle of emergence is 46 The angle of minimum deviation will be 1 Less than 41 3 More than 41 2 Equal to 41 4 None of the above

They co ordinate of the centre of mass of the system of three rods of length 2a and two rods of length a as shown in figure is Assume all rods to be of uniform density 1 B 28 9a 2 16 3 a M y 29 0 W 87 14 8a 4 3 3 zero placed on a smooth horizontal surface and a horizontal force F is applied on it at a distance

minimum deviation takes place 2 60 45 30 4 75 A ray of light is incident at angle of 60 on one face of a prism which has an apex angle of 30 The ray emerging out of the prism makes an angle of 30 with the incident ray The refractive index of the material of the prism is 1 2 3 3 1 5 4 1 6

In the figure given the position time graph of a particle of mass 0 1 kg is shown The impulse at t 2 s is x m 4 2 2 t s 1 0 2 kg m s 2 0 2 kg m s 6 3 0 1 kg m s 4 0 4 kg m s AIIMS 2005

24 2 7 kg 3 17 kg 4 3 kg The force F acting on a particle of mass m is indicated by the force time graph shown below The change in momentum of the paticle over the time interval from 0 to 8 s is NEET 2014 1 24 N s 2 20 N s F N 4 6 3 s 3 12 N s 4 6 N s 2x6x2 x3 42x3 6 6

An ideal gas has 3 rotational degrees of freedom and 3 translational degrees of freedom The ratio of molar specifi heat of the gas at constant pressure to that at constant volume will be 43 2 5

A ball collides with an inclined plane of inclination 0 after falling through a distance h If it moves horizontally just after the impact the coefficient of restitution is 1 tan 0 2 cot 0 3 tan 0 4 cot 0 A solid iron ball A of radius r collides head on with another stationary solid iron ball B of radius 2r The ratio of

1 28 ms On a frictionless surface a block of mass M moving at speed v collides elastically with another block of same mass M which is initially at rest After collision the first block moves at an angle 9 to its initial direction and has NEET 2015 a speed v 3 The second block s speed after the collision is 2 5 3 2 2 3 4

13 Some structural members subjected to a long time sustained loads deform progressively with time especially at elevated temperatures What is such a phenomenon called a Fatigue b Creep c Creep relaxation d Fracture I

46 Which of the following relation s is are always correct p linear momentum dv dm dp dt 4 F m v dv dm dt dt dt dt of more 3 kg moving with a speed of 100 m s strikes a wall at an angle 60 as shown in figure 1 thrust u Urel 2 F m 3 F m

6 The body will regain it is ious shape and size only when the deformation caused by the external forces is within a certain limit What is that limit a Plastic limit b Elastic limit c Deformation limit d None of the mentioned