Basic Physics Questions and Answers

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

wing are correct a a b c and d must each be a null vector b The magnitude of a c equals the magnitude of b d c The magnitude of a can never be greater than the sum of the magnitudes of b c and d d b c must lie in the plane of a and d if a and d are not collinear and in the line of a and d if they are collinear

P a 24 55 kg H 0 37 k 0 29 P 272 N Since the magnitude of Fis less than Fmax our assumption of no motion is confirmed The crate does not move What is the acceleration in this case Answer m s

Two blocks of mass 2 9 kg and 1 9 kg are suspended from a rigid support S by two inextensible wires each of length 1 m see figure The upper wire has negligible mass and the lower wire has a uniform mass of 0 2 kg m The whole system of blocks wires and support have an upward acceleration of 0 2 m s2 The acceleration due to gravity is 9 8 m s 1989 6M 2 9 kg 1 9 kg a Find the tension at the mid point of the lower wire b Find the tension at the mid point of the upper wire

QNo 129 Mark for revie The attractive force that binds protons and neutrons in nucleus of an atom is known as electromotive force coulomb force electromagnetic force nuclear force

A load of 40 kg is suspended from a wire of radius 10 m and density 8 10 kgm 75 of the work done 3 to increase the length is converted into heat Calculate the change in temperature in kelvin of the wire Given that Y 7 5 10 0 Nm 1 and heat capacity of the material of the wire is 490 Jkg K respectively Take 9 8 and g 9 8 m s

Three identical small balls each of mass 0 1g are suspended at one point on silk thread having a length of 1 20cm What charges should be imparted to the balls for each thread to 30 with the vertical form an angle of a

Two blocks each of mass M are connected to the ends of a light frame as shown in figure 7 W6 The frame is rotated about the vertical line of symmetry The rod reaks if the tension in it exceeds To Find the maximum will not requency with which the frame may be rotated without reaking the rod a 4 length of the rod amais the elementlying cents nous move to provide M masoms the rodbeyond it M 1 also note s frequency not g

Question 4 4 points A survey of a random sample of voters shows that 66 plan to vote for Katie and 34 plan to vote for Casey The survey has a margin of error of 2 What is the range for the percentage of voters who plan to vote for Katie

A fluid at 5 bar and with specific volume of 0 2 m kg expands in an engine reversibly to a pressure of 1 2 bar following the law P C v where Cis constant Find the work done during the process

The speed of a car as a function of time is shown in figure 3 E1 Find the distance travelled by the car in 8 seconds and its acceleration Speed in m s 20 10 0 2 4 6 8 10 Time in second Figure 3 E1

A coil has an inductance of 0 7 henry and is joined in series with a resistance of 220 2 When the alternating emf of 220 V at 50 Hz is applied to it I then the phase through which current lags behind the applied emf and the wattless componenet of current in the circuit will be respectively AMU 2000 1 30 1 A 2 45 0 5 A 3 60 1 5 A 4 none of these

1 A block of mass 2M is attached to a massless spring with spring constant k This block is connected to two other blocks of masses M and 2M using two massless pulleys and strings The accelerations of the blocks are a a2 and a3 as shown in the figure the system is released from rest with the spring in its unstretched state The maximum extension of the spring is xo Which of the following option s is are correct g is the acceleration due to gravity neglect friction A a2 a a a B At an extension of of the spring the Xo 4 magnitude of acceleration of the block 3g 10 connected to the spring is 4Mg k to the spring is 3g fo M 5k 0000000 2M a M C Xo Xo D When spring achieves an extension of for the first time the speed of the block connected 2 2M 2019

Two thin plano convex lenses of focal length f m in air are placed at some distance d from each other as shown in the figure The space between the lenses are filled with a substance with refractive index The distance d between the lenses are so adjusted that a parallel beam of light passing through such an optical system remains parallel Refractive index of lens u 3 What is the appropriate relation between u d

Two moving particles P Q are 10 m apart at any instant Velocity of P is 8 m s and that of Q is 6 m s at 30 angle with the line joining P Q Calculate the angular velocity of P w r t Q 1 2 Question Type Single Correct Type 3 P 4 30 0 1 rad sec 0 7 rad sec 0 5 rad sec 30 1 0 rad sec

To decrease the cut off wavelength of continuous X rays by 25 the potential difference across X ray tube 100 3 3 must be increased by 25 1 must be increased by 100 2 must be decreased by 3 4 must be decreased by 25

A sphere of radius 0 1 m and mass 87 kg is attached to the lower end of a steel wire of length 5 0 m and diameter 103 m The wire is suspended from 5 22 m high ceiling of a room When the sphere is made to swing as a simple pendulum it just grazes the floor at its lowest point Calculate the velocity of the sphere at the lowest position Y for steel 1 994 x 10 Nm 2 a 5 42 m s 1 c 10 54 m s b 1 22 m s d 8 74 m s 1

Example 2 In an interference pattern with two coherent sources the amplitude of the intensity variation is foun be 5 of the average intensity Calculate the relative intensities of the interfering sources

For traffic moving at 60 km h if the radius of the curve is 0 1 km what is the correct banking angle of the road g 10 m s estion Type Single Correct Type 1 2 3 tan 1 3600 tan 1 5 36 tan 1 10 36

Quiz Vector is the resultant of vectors and B Select correct statement about their magnitudes 2016 A C may be equal to A B C A and C B X O given D C cannot be less than the smallest among A and B X C C A B

A pipe of length 1 5 m closed at one end is filled with gas and resonates in its fundamental mode with a tuning fork Another pipe of same dimensions filled with air resonates in its fundamental mode with same tuning fork If experiment is performed at 30 C speed of sound in air is 360 m sec the velocity of sound at 0 C in gas is A 580 m sec C 880 m sec B 680 m s D none

In the given circuit the switch is closed to the position bc from the earlier position of ac at t 0 The current in the inductor after 2s of closing the switch between b and c is A 1 2 19e A 10V T B 10e A a Ob 19 www L 1H C 10e A D 10e A

12 A fully charged capacitor C with initial charge qo is connected to a coil of self inductance L at t 0 The time at which the energy is stored equally between the electric and the magnetic fields is 1 T LC 3 2n LC TC 2 LC 4 4 IC

Dar magnet of magnetic moment 5 3x10 JT is placed with its axis normal to the earth s horizontal magnetic field The distance from the centre of magnet at its equatorial position where the resultant field makes an angle 60 with earth s horizontal field is BH 0 4 10 4 T NCERT Pg 180 1 5 3 cm 2 5 cm 1 3 5 6 cm 4 10 cm

The work by electric field during the displacement of a negatively charged particle towards a fixed positively charged particle is 9 J As result the distance between the charges has been decreased by half What work is done by the electric field over the first half of this distance a a 3 J b 6 J c 151 d 9 J JIPMER

An organ pipe open at both ends is oscillating in fifth overtone The separation between two points where pressure amplitude is 1 2 times the pressure amplitude at the anti nodes is 10cm The length of the organ tube is Take speed of sound in air to be 330 m s A B C 40 cm 80 cm 100 cm 120 cm YOU MARKED X

Case Passage 11 Consider a region of cylindrical magnetic field changing with time at the rate x A triangular conducting loop PQR is placed in the field such that mid point of side PQ coincides with axis of the magnetic field region PQ 21 PR 27 73 The emf induced in the side PQ of the loop is a 0 b xf c 2 74 The emfinduced in the side QR of the loop is x1 x b a 0 b xf c 75 The emf induced in the side PR of the loop is a xf c d 2x 2 d 4x 2 d zero

A particle executes SHM of amplitude 5 cm and period 3 s The velocity of the particle at a distanc 4 cm from the mean position taken 3 is 1 8 cm s 2 12 cm s 3 4 cm s 4 6 cm s

questions Each question has 4 choices 1 Read More avg is average speed and Vrms is root mean sq eed of molecules of ideal gas then the ratio o g Vrms is 3 5 OF 2 3n

Phy Section B This section contains 15 SINGLE CORRECT T questions Out of these 15 questions candidat Read More solving power of a microscope is maximum for Red light O Green light OBlue light Orange light

The oscil surface is represented by the equation X Acos wt where X displacement at time t frequency of oscillation Which one of the following graphs shows correctly the variation acceleration a with t AIPMT 2014 1 3 O 48 a O a C T T T horizontal t Au cosut

18 A horizontal ring of radius r 1 2 m is kept in a vertical constant magnetic field 1 T The ring is collapsed from maximum area to zero area in 1 s Then the emf induced in the ring is 1 1 V 3 2 V 2 4 V 4 TV

11 In the diagram man A and man B are both standing on weighing machines Both the men have same mass M They are both holding on the strings as shown The reading of the weighing under the man A is M What will be the reading of the other weighing machine A M M B M 2M D None C 2M M

me pressure in a monoatomic gas increases 3Po when its volume increases from Vo to 2 Crease in internal energy is P 0 15PV V 2V 21 5P Vo 212 5P Vo O5P Vo B Read More

13 In an AC circuit the voltage applied is E E sin oor The resulting current in the circuit is I Io sin ot 2 The power consumption in the circuit is given by Eolo 1 P 0 2 P 2 3 P 2 Eolo Eolo 2 4 P

4 2 5 3 An object is placed at a distance of 30 cm from the pole of a convex mirror If the radius of curvature of the mirror is 60 cm then the image will be formed at from pole 1 Infinity 2 15 cm 3 30 cm 4 20 cm 4 2 5 3 30 d af 60 cm 1 2 15 cm 3 30 cm 4 20 cm

A satellite of mass m was originally placed into an orbit of R and a period of T around planet Express the mass of this planet M in terms of the Universal constant G the radius R and the period T M 4 2 R 3 G T 2 M 4 2 G R 3 T 2 OM 2 G R 3 T 2 OM R 3 G T 2 5

9 Two resistors of 10 22 and 20 22 and an ideal inductor of 10 H are connected to a 2 V battery as shown in figure Key K is inserted at time t 0 The initial t 0 and final t currents through the battery are 1 3 1525 A A 10 1 10 A 2 V 10 H morr www 10 Q2 2 4 10 A A 20 Q 15 2 A

A stone tied to the end of a 80cm long string is whirled in a horizontal circle with a constant speed if the stone makes 14 revolution in 25sec the magnitude of its acceleration is estion Type Single Correct Type 1 2 3 20 m s 12 m s 9 9 m s

14 A 300 S2 resistor is connected in series with a parallel plate capacitor across the terminals of a 50 0 Hz ac generator When the gap between the plates is empty its capacitance is 70 22 F The ratio of the rms current in the circuit when the capacitor is empty to that when ruby mica of dielectric constant k 5 0 is inserted between the plates is equal to 1 0 1 2 0 3 4 29 3 0 6

The efficiency of heat engine is 25 percent If 50 000 Joules of heat is supplied to the engine therefore the useful work done by the engine is 1 12500 Joules 2 25000 Joules 3 51200 Joules 4 21500 Joules

4 2 PA 7 Two vessels of the same volume contain the same gas at 37 same temperature If the pressure in the vessels be in the ratio of 1 2 then 1 the ratio of the average kinetic energy is 1 2 2 the ratio of the root mean square velocity is 1 1 3 the ratio of the average velocity is 1 2 4 None of these 4 2 PA trata 1 2 1 2 3 4 1 2 f 1 2 11

16 The self inductance of a choke coil is 10 mH When it is connected with a 10 V dc source then the loss of power is 20 watt When it is connected with 10 volt ac source loss of power is 10 watt The frequency of ac source will be 1 50 Hz 2 60 Hz 4 100 Hz 3 80 Hz

i Find the moment of inertia of a cylinder of mass Mradius R and length L about an axis passing through its centre and perpendicular to its symmetry axis Do this by integrating an elemental disc along the length of the cylinder MR ML kasalo

15 A resistance of 20 2 is connected to a source of an alternat ing potential V 220 sin 100 t The time taken by the current to change from the peak value to rms value is 1 0 2 s 2 0 25 s 3 2 5 10 s 4 2 5 10 s

4 2RBV and Q is at higher potential 2 Plane figures made of thin wires of resistance R 50 milli ohm metre are located in a uniform magnetic field perpendicular into the plane of the figures and which decrease at the rate dB dt 0 1 mT s Then currents in the x D x inner and outer boundary are The inner radius a 10 cm and outer radius b 20 cm 1 10A Clockwise 2 x 10 4 A Clockwise AY A X X X X X X X X b a X X X X X X X X 2 10 4 A Anticlockwise 2 x 10 4 A Clockwise 3 2x 10 4 A clockwise 10 4 A Anticlockwise 10 4 xC x X X X X X

20 A typical light dimmer used to dim the stage lights in a theatre consists of a variable induction for L where inductance is adjustable between zero and Imax connected in series with a light bulb B as shown The mains electrical supply is 220 V at 50 Hz the light bulb is rated at 220 V 1100 W What Lmax is required if the rate of energy dissipation in the light bulb is to be varied by a factor of 5 from its upper limit of 1100 W 1 0 69 H 3 0 38 H Imp to mains 2 0 28 H 4 0 56 H Bulb

A particle is released from a height H At a certain height its kinetic energy is two times its potential energy Height and speed of particle at that instant are Question Type Single Correct Type 1 2 3 H 2gH 3 3 51210 gH 3 2H 2gH 3 3