Physics Questions

9 A mosquito net over a 7 ft x 4 ft bed is 3 ft high The net has a hole at one corner of the bed through which a mosquito enters the net It flies and sits at the diagonally opposite upper corner of the net a Find the magnitude of the displacement of the mosquito b Taking the hole as the origin the length of the bed as the X axis its width as the Y axis and vertically up as the Z axis write the components of the displacement vector

2 on ground both apply Newton s law and measure normal reaction on the body 0 m 79 7777 7777 1 The both measure the same value 2 The both measure different value 3 The both measure zero 4 Not sufficient data IS

34 The given figure shows a spherical Gaussian surface and a charge distribution When calculating the flux of electric field through the Gaussian surface then the electric field will be due to a 93 alone c 9 93 and 92 b q and 93 d q and 9 91 1 92 AMU 2012

4 9 8 x 10 N m A mild steel wire of length 2 meter cross sectional area A m is fixed horizontally between two pillars A small mass m kg is suspended from the mid point of the wire If extension in wire are within elastic limit Then depression at the mid point of wire will be 1 3 1 M9 Mg 3 4 Mg IA Mgl YA Mg 2YA 1 3 1 3

Uniform and non uniform acceleration both Which of the following statement is 3 INCORRECT I For motion involving change in direction along the straight line displacement may decrease II Direction of acceleration is same as direction of velocity III Average speed is in general greater than or equal to the magnitude of the average velocity IV Equation of motion is valid only in one dimensional uniform accelerated motion 1 only I 5 II IV 2 only IV 4 I III IV

If photon energy is near about 3 5 eV then it causes the sunburn i e to break the bond in molecules of human ski This corresponds to the wavelength in the O X ray region O Visible region O IR region Ouv region

e A ball of mass m is suspended by a massless string of length from a fixed point A ball of mass 2m strikes in the direction of 0 45 from horizontal sticks to it 2m 45 m the initial velocity of 2m is x g so that system deflects by the velocity at highest point of trajectory is V then find x y and if string is cut at 6 60 and 2

Question 2 A particle approaches from very large distance towards concave mirror along the principal axis By the time the particle reaches the mirror the distance between the particle and its image B C first decreases then increases first increases then decreases first increases then decreases and then again increases first decreases then increases and then again decreases My Answer Correct Answe

A block of mass 2 kg is moved on a frictional horizontal plane by applying horizon of 10 N The coefficient of friction is 0 2 The kinetic energy of block after it has m distance of 10 m is Options 100 J 2 40 J B 20 J

The displacement of a pendulum is the angle measured from the vertical For a certain pendulum the displacement is 8 16 sin 4t 0 754 where is measured in radians Determine the maximum angle from the vertical position

In the given figure a block A rests on a smooth triangular block B and the block B is moved at an acceleration of a 2 m s along the plane A normal force on block A due to block B is m g a B Acceleration of block A relative to block B is acos 0 A B If friction is present between block A and B the coefficient should be greater than C cose for no relative motion between A and B If friction is present between block and A and B the coefficient of friction should be a cos 0 D greater than g a sin 0 2 for no relative motion between A and B Q 2

A battery of internal resistance one ohm and emf 3 volt sends a current through Imetre of uniform wire of resistance 50 The poles of the cell of emf 1 4volt are connected to two points on the wire so that no current passes through this cell Then the potential gradient of the wire is

AB Determine the resistance RR between points A and B of the frame made of thin homogeneous wire figure assuming that the number of succes sively embedded equilateral triangles wide sides decreasing by half tends to infinity Side AB is equal to a and the resistance to unit length of the wire is p a 2 a 2 B

What is correct answer Q 2 Two pipes are connected by a manometer as shown in the figure below Differential readings are 03 0 7 m and 10 m as shown on the figure Determine the pressure difference PA PB between pipes A and B 30p Water 4 0 3 m 0 7 m fluid SG 2 Water 10m

ubwards with speed vo The variation of speed with time is best represented by which of the following graph VA 445 3 2 Vo Vo fu

26 180 The colour of bright fringe nearest to central white fringe in interference pattern with white light will be X Blue Red Yellow

from the centre of a uniform sphere of 54 The magi 12 and 71 radius R and mass M are F and F2 respectively Then more than one are correct F if R and r R 12 a b c F2 F F2 2 i if 2 12 F2 12 R and 2 R F 2 if R and r R 1 F2 if R and r R al force at distances moita

94 In the given figure the block is moved to compress the spring by 3 2 cm from the shown natural length and released If the collision with the wall is elastic the time period of oscillation will be Here T is time period if wall would not have been there

For a black body maintained at temperature To K the maximum radiation occurs at wavelength o If the temperature is raised to T K To 2 corresponding wavelength is If Ao 3000 then value of o is O 8 000 6 000 O 9 000

Three long wires are placed along X axis Y axis and Z axis and they carry equal current in positive direction The magnetic field produced due to them at point a a 0 has magnitude 2 1 3 Ho 2 a 3 ol Am 4 Ho 4 2 a Ho

The position of a particle is given as 7 at bt 1 Find the a Equation of trajectory of the particle ns y bx a b Tangential normal acceleration and radius of curvature at t 1 sec 4b Re 462 3 2 la 4b 2ab ns a t an 2ab Va 4b 2

Part A options left to right or right to left Consider the parametric equations below x t 6 y t 3 a Describe the motion of the particle moving according to the parametric equations The motion of the particle is from Choose one b Find the equation of the curve along which the particle moves NOTE Enter the exact value

On an X temperature scale water freezes at 125 X and boils at 375 X On a Y temperature scale water freezes at 70 0 Y and boils at 30 0 Y The value of temperature on X scale equal to the temperature of 50 Y on Y scale is

In the given arrangement all strings and pulleys are ideal When system was released it was observed that m1 m2 do not move Then 5 1 m1 m3 m1m4 4m3 M4 3 m2 m3 m3m4 2m3 M4 M1 m m3 M4 2 m2 m3 m2m4 2 m m4 4 m1 m3 m1m4 8 m m4 Space for Rough Work

V IV A IV 39 ww Hr 0 VB 2 OB 5V ww 7 592 6V wwwc 552 C Vc 6V In the above diagram 1 Potential at junction O is zero 2 Current in 392 is 2A 3 Current in 5 Q2 is 2 3 A 4 All the above are correct

7 A projectile is projected with a speed u making an angle 20 with the horizontal What is the speed when its direction of motion makes an angle 0 with the horizontal u cos 20 2 1 2 u 2 cos 0 sec 0 3 u cos 0 4 u cos 0 sec 0 A particle reaches its heghest point when it has

Two mutually perpendicular simple harmonic vibration of same frequency superimpose on each other The amplitude of two vibration is different and T they are differing each other in phase by resultant of superposition is 1 Parabola 2 Straight line 3 Elliptical A Circular The

11 The electric field in a certain region is given by E 51 3 kV m The potential difference VB VA between points A and B having coordinates 4 0 3 m and 10 3 0 m respectively is equal to 1 21 kV 3 39 kV 2 21 kV 4 39 kV

4 A point charge Q is placed at the centre of a hemisphere Find the ratio of electric flux passing through curved surface and plane surface of the hemisphere a 1 1 b 1 2 c 2 1 d 4 1

d none of these 60 A black spot is present at the center of the face of an equilateral prism A man placed his eye close to the opposite corner He sees two images of the spot at an angular separation of 60 What is the condition on the refractive index of the prism very Eye a 2 b 2 Black spot c 2 3 d 2 3

9 In a certain hypothetical radioactive decay process species A decays into species B and species B decays into species C according to the given reactions A 2B particles energy B 3C particles energy The decay constant for species A is A 1 sec and that for species B is A 100 sec Initially 104 moles of species of A were present while there were none of B and C It was found that species B reaches its maximum number at a time to 2 In 10 sec Calculate the value of 0 maximum number of moles of B

The length of each side of a cubical closed surface is L If the charge Q 24 Eo In SI unit is situated at vertex of cube as shown then the flux passing In SI unit through shaded face of the cube is

Two semicircular thin wires of radii R and R2 having same origin O are uniformly charged with charge density A and A2 as shown in the figure If the net field at O is zero when R 1 3 R2 then find the ratio A1 A2 O P

1 In LCR series circuit source voltage is 120 V and voltage across inductor is 50 V If voltage drop across resistance is 40 V then determine voltage in capacitor a 10 5 8 2 v c 20 5 8 2 V b 10 5 8 2 V d 10 5 7 2 V AIIMS

2 10 m s 4 10 m s 3 15 m s A lift coming from 8th floor is just about to 4th floor and stops on 4th floor Taking as origin and taking upward direction as p for all quantities which of following is c 1 x 0 v 0 a 0 2 x 0 v 0 a 0 3 x 0 v 0 a 0

SolveLancer Test A particle moves rd of total distance with an acceleration 10 m s starting from rest The remaining distance cover with constant velocity then find the ratio of time required to cover remaining distance and the total time Here total distance is 120 m SolveLancer Test a 1 5 b 1 4 c 2 5 4 23 0 a

A2 cm high object is placed on the principal axis of a concave mirror at a distance of 12 cm from the pole If the image is inverted real and 5 cm high The location of the image and the focal length of the mirror is NCERT 1 30 cm 8 6 cm 3 30 cm 10 cm 2 8 6 cm 30 cm 4 10 cm 30 cm

A boy tries to cross the river and want to reach at the exactly opposite point on the other bank then what is the necessary relation between v and v I V velocity of boy v velocity of river b 1 v V 2 V V 3 V V 4 None of these

A particle P is moving on a circle under the action of only one force which always acts at the towards a fixed point O lying on the circumference Find ratio of moment when 0 45 C is centre of circle L de to

2 Three rods equal length 1 connected in such away 42 that they from an equilateral triangle PQR Q be the mid point of PQ and OR remains constant for small in increment of temperature Linear expn coefficienents of PR and PQ are same a and linear expn coefficients of PQ is than 1 4 3 3 p4 R 2 3 4 4

1 sketch a graph that shows the proper relationship Case A Gravitational Potential Energy Eg Total gravitational potential energy is zero at infinity Gravitational potential energy is negative Maximum value is zero

above the target 2 Pass below the target 3 Hit the target 4 Certainly miss the target Neglecting the air resistance the time of fligh of a projectile is determined by u 1 Uvertical component of velocity in vertica direction 2 Uhorizontal component of velocity in horizonta direction 3 u u u 4 u u u vertical inal horizontal 1 2

An infinitely long wire carrying a current I in vertically upward direction y direction is placed near the surface of earth as shown in figure Neglect the earth s magnetic filed Y A O a 0 At some time t a particle is at point A a 0 and moving towards origin with velocity V If the acceleration of particle at point A is 2g in downward direction then B X particle is negatively charged particle is positively charged YOU MARKED

The velocity time graph of two particles moving along x axis is shown in figure At t 0 both were at origin During first 4 sec the instant when they are at maximum separation and the maximum separation are V m s 1 2 sec 4m 4 3 2 2 2 sec 32 7m t sec 3 16 7 sec 32 7 m 4 16 7 sec 4m

hree point charges are placed at the corners of a rectangle as shown in figure If a 54 cm and q 25 C then calculate the magnitu lectric force in N on the charge 3q 9 a 9 2 a 4q Useful constants k 9 00 109 N m C 0 8 85 10 12 c N m HO 4TTx 10 7 T m A mp 1 67 10 27 kg me 9 11 10 31 kg e 1 6 10 19 C 100m 2

X The position of a particle varies with time as x t 1 e t where Vo Vo B is a positive constant and 0 Dimensions of Vo and 3 are respectively O MOLT and T MOLT and T MOLTO and T 2 M L T and T

4 8 0 m from the person A ray of light is incident at 50 on the middle of one of the two mirrors arranged at an angle of 60 between them The ray then touches the second mirror get reflected back to the first mirror making an angle of incidence of 1 50 2 60 3 70 4 80

20 If a semiconductor has an intrinsic carrier concentration of 1 41 x 10 6 m3 when doped with 1021 m3 phosphorus then the concentration of holes at room temperature will be 1 2 10 1 3 1 41 10 0 2 2 10 1 4 1 41 10 6

75 m A concave mirror has a focal length 20 cm The distance between the two positions of the object for which the image size is double of the object size is 3 30 cm 4 60 cm 1 20 cm 2 40 cm An object is placed on the princi

5 In the following the diodes are either forward biased or reverse biased Choose the correct statement 8V9 www I A wwww 4V 6 8V 8V www II 8 Vo D III IV a I and II are forward biased and III and IV are reverse biased b I and IV are forward biased and II and III are reverse biased c I and III are forward biased and II and IV are reverse biased d II and III are forward biased and I and IV are reverse biased