Basic Physics Questions and Answers

An inductor of inductance L a capacitor of capacitance C and a resistor of resistance R are connected in series to an ac source of potential difference V volts as shown in figure Potential difference across L C and R is 40 V 10 V and 40 V respectively The amplitude of current flowing through LCR series circuit is 10 2 A The impedance of the circuit is T 2 3 g V 15 2 0 n 40 50 4 2 02 40 V10 V 40 V

V V b nRT where P V R T and n represent the pressure volume universal gas constant absolute temperature and number of moles of a gas respectively a and b are constants the ratio b a will have the following dimensional formula A M L 7 B M L T 1 MI T 272 D MIT

A force of 30 N acts on a body at rest of mass 10 kg for 60 seconds If the distance travelled in first 20 s is x next 20 s is x2 and the last 20 s is x3 then X X2 X3 will be equal to A 1 1 1 B 1 3 5 c 1 4 9

2 Three pipes with the same length and circular cross section are connected to each other as shown in figure 2 Suppose L 100 0 m and radius of the pips is 20 0 cm and the density and viscosity of water in the pipe are p 1000 kg m and n 1 8 x 10 Pa s Find P if P 2 0 atm h 0 5 m and v 30 0 m s pi Vi ri L h L Figure 2 Problem 2 L P2 V2 12

10 State Kirchhoff s rules Apply these rules to the loops PRSP and PRQP to write the expressions for the currents I1 I2 and I3 in the given circuit S 5V 1 13 200 22 www R www wwww 20 92 milliammetre 60 Q C

12 A diatomic gas with three moles are in a container at 400 K Under isobaric process its temperature is changed to 900 K How much heat is absorbed by the gas during this process NCERT Pg 312 1 6 4 kcal 2 9 4 kcal 3 10 4 kcal 4 12 4 kcal Which of the following is incorrect statement 1 a i 2 a iv 3 a iv 4 a iv 15 Molar consta specific 35 joul

in ts 5 15 What will be mean free path of a nitrogen molecule in a container at 2 atmospheric pressure and at 17 C radius of nitrogen molecule is about 1 NCERT Pg 337 Molar mass of nitrogen 28 0 u 1 1 11 x 10 7 m 2 2 3 x 10 6 m 3 2 4 x 10 7 m 4 1 8 x 10 9 m 16 Air has density of 1 3 km m 3 and 1 1 2 1 3 1 4 1 19 A po rotat vibra heat 1 4

If resistances are connected in series then Equivalent resistance will be 300 8 error in equivalent resistance will be 2 7 Equivalent resistance will be 300 2 error in equivalent resistance will be 3 4

A Man Maging Equilibrium of a Block A man A 30 kg standing on a platform and holding a string If platform strings and pulleys are light find the force man needs to exert on string he is holding to keep himself at rest on platform A 2 11 2

Three identical metal plates with large surface areas are kept parallel to each other as shown in figure The leftmost plate is given a charge Q the rightmost a charge 2Q and the middle one remains neutral If Q 2 then find the magnitude of charge appearing on the outer surface of the rightmost plate

Three concentric conducting spherical shells have radius r 2r and 3r and Q Q and Q are final charges respectively Innermost and outermost shells are already earthed as shown in figure Then 37 2 2 Q Q Q ALD

In the circuit the battery is ideal A voltmeter is connected in turn across R and R giving readings of V and V respectively A B Select answers C E 120V D R www R www 600 2 300 V 60 V V 80 V V 30 V V 40 V

Three voltmeters all having different resistances are joined as shown in the figure When some P d is applied across A and B their readings are V V and V3 respectively Then A Select answers A V V B C D V V V V2 V3 V V V3 B

Example A balloon has a mass of 10 gram in air The air escapes from the balloon at a uniform rate with a velocity of 5 cm s and the balloon shrinks completely in 2 5 s Calculate the average force acting on the balloon Solution Here m 10 gram v 5 cm s dm dt F 10 2 5 dp dt 4 gram sec F d dt mv dm dt 20 dyne v 4 x 5

A train is going fast a station with a speed of 5 ms 1 towards positive X axis A particle resting on the floor of tra is given an acceleration of 4 ms 2 in a direction perpendicular to train s motion the trajectory of the particle see by an observer on the platform is a Circle b Ellipse d Hyperbola c Parabola

A wire of length 5 m and radius 1 mm has a resistance of 1 ohm What length of the wire of the same material at the same temperature and of radius 2 mm will also have a resistance of 1 ohm Select an answer A B C D 1 25 m 2 5 m 10 m 20 m

The displacement of a body along y axis is given by 2y gt g is a constant t is the time taken What will be the acceleration of the body along y axis at any time t A g B 1 28t 20

9 An aluminium sphere of mass 47 gm is at 100 C It is then transferred to 140 gm copper calorimeter containing 250 gm of water at 20 C In steady state the temperature of water rises by 3 C What is specific heat of aluminium if that of copper is 386 J kg 1 K 1 NCERT Pg 286 8 1 911 J kg 1 K 1 2 516 J kg 1 K 1 3 312 J kg K 1 4 612 J kg K 1 Two ideal gas thermometers A and B use now being utilised to liquid state to vapou condition specific hea 1 Less than zero 2 Zero 3 Slightly greater 4 Infinite 12 Certain amount of h copper to increase If same amount of

2 A 20 cm thick planoconcave lens is placed on 32 a paper on which flower is drawn How far above its actual position does the flower appear to an observer looking down normally from top 1 10 cm 3 50 cm R 20cm Observer r 20cm air 2 15 cm 4 None of these TO

Displacement of a particle as a function of time t is given by s a t yt 8t4 where a y and 8 are constants Ratio of initial velocity to initial acceleration is Question Type Single Correct Type 1 2 217

Warm up problems Problems 3 32 and 3 34 from Knight a A cannon tilted upward 30 fires a cannonball with a speed of 100 m s What is the component of the cannonball s velocity parallel to the ground about 87 m s b Jack and Jill ran up the hill at 3 0 m s The horizontal component of Jill s velocity vector was 2 5 m s What was the angle of the hill and the vertical component of Jill s velocity 34 1 7 m s Careful measurements have been made of Olympic sprinters in the 100 meter dash A quite realistic model is that the sprinter s velocity is given by v a 1 ebt where t is in 5 v is in m s and the constants a and b are characteristics of the sprinter Sprinter Carl Lewis run at the 87 World Championship is modeled with a 11 81 m s and b 0 6887 s Problem 2 82 from Knight a What was Lewis acceleration at t 0 s 2 00 s and 4 00 s 8 13 2 05 and 0 52 m s b Find an expression for the distance traveled at time t x bt e bt 1 c Your expression from part b is a transcendental equation meaning you can t solve it for t However it is not hard to use trial and error to find the time needed to travel a specific distance To the nearest 0 01 s find the time Lewis needed to sprint 100 0 m His official time was 0 01 s more

AllS 1 JJ era 6 The apparent depth of an object at the bottom of a tank filled with a liquid of refractive index 1 3 is 7 7 cm What is the actual depth Ans 10 cm

2 89 6 J 4 142 5 J 3 42 05 J A cylinder with movable piston contains 2 moles of hydrogen at standard temperature and pressure The cylinder walls of the cylinder are made of heat insulator By what factor does the pressure of a gas increase when gas is suddenly compressed to half of its original volume NCERT Pg 321 1 1 5 2 3 82 3 2 64 4 6 23 Two cylinders A and B of equal capacity are connected to each other via a stopcock A Pressure O 400 C 1 500 J 3 1200 J F 1 0 TI 11 A steam eng engine deliv minute and minute from temperature

1 gm of water is changed from its liquid to vapour phase The measured latent heat of water is 2256 J g What is the amount of change in internal energy NCERT Pg 308 1 169 2 J 2 3068 2 J 4 2548 3 J 3 2086 8 J A monoatomic ideal gas undergoes an adiabatic process from temperature 300 K to 600 K The gas has 2 moles calculate work done by this ideal gas NCERT Pg 312 2 200 R J RA PM 600 R D 6 A 7 What amount of 2 x 10 2 kg of nitr to raise its tempe pressure Molec 1 270 5 J 3 370 4 J In changing the from an equilib equilibrium state 6 i 222128

9 A mercury thermometer is kept at the focus of a concave reflector behind its bulb as shown in the figure and in front of an electric furnace Which of the following combinations will cause the smallest reading of the thermometer Thermometer Radiation Electric Furnce Reflector 1 Black reflector and black bulb 2 Black reflector and shiny bulb 3 Shiny reflector and shiny bulb 4 Shiny reflector and black bulb

d to half of T Pg 321 pacity are opcock A ature and ated The ated The at is effect Pg 321 11 A steam engine working like an ideal heat engine delivered 5 4 x 108 J of work per minute and takes 3 6 109 J of heat per minute from its boiler at 127 C What is sink temperature NCERT Pg 322 1 37 C 2 47 C 3 57 C 4 67 C Dh 011 17633156

A train is going fast a station with a speed of 5 ms towards positive X axis A particle resting on the floor of trai is given an acceleration of 4 ms2 in a direction perpendicular to train s motion the trajectory of the particle see by an observer on the platform is a Circle b Ellipse Hyperbola C Parabola d

The percentage errors in the measurement of mass and speed are 2 and 3 respectively How much will be the maximum error in the estimation of KE obtained by measuring mass and speed Question Type Single Correct Type 1 2 3 5 1 8

Six resistance are connected as shown in figure 502 A 60 ww B www 40 Voltage difference between A B 4 V 15 V Select an answer 3 V A 4Q 1 Based on above figure solve these questions www 60 I B www 15 0

If a ai and b bi b j and b bi b j and b a b c d a va b 2 2 b b a 2 a b N a a kand b b None of the above and and A and both both a and b are parallel to each other Then a2 2 2 a a2 b2 2 2 a a2 b2 b b a b b

16 Air has density of 1 3 kg m and temperature of air is 37 C If molar mass of air is 28 8 what will be air pressure NCERT Pg 326 t 1 1 16 x 105 N m 2 2 1 x 104 N m 3 1 92 x 105 N m 4 0 92 x 105 N m 17 The ratio of degrees of frondom 20

A bus starts moving with acceleration 2 ms 2 A cyclist 96 m behind the bus starts simultaneously towards the bus at 20 m s After what time will he be able to overtake the bus Question Type Single Correct Type 1 4 s 28 s 3 12 S

A particle moving along X axis is having position time graph as shown in figure x m 54 362 2 5 Based on shown graph answer the following question sec

A man who can swim with a velocity V b in still water wants to cross a river in minimum possible time If the river is flowing with a velocity v and b x are the width and drift respectively the actual distance travelled by the man is 42 2 2 2 2

A certain prism is found to produce a minimum deviation of 38 It produces a deviation of 44 when angle of incidence is either 42 or 62 What will be the angle of incidence when it undergoes minimum deviation I 1 45 2 49 3 40 4 55

4 612 J kg K 1 10 Two ideal gas thermometers A and B use oxygen and hydrogen gas respectively Following observation were made Temperature Pressure thermometer A Triple point of 1 25 x 105 Pa water Normal melting point of sulphur 1 797 x 105 Pa Pressure thermometer B 2 x 10 Pa 2 87 x 10 Pa What is absolute temperature of normal melting point of sulphur as read by thermometer A and B respectively INCERT Pa 3001 12 Certain copper to increase its temperature by If same amount of heat is given to 60 water then rise in its tempera Specific heat of copper 385 J kg water 4200 J kg 1 K 1 NCERT 1 4 C 2 5 C 3 6 C 4 9 C 13 When 150 gm of ice at 0 C is mi 300 gm of water at 50 C in a conta resulting temperature is Lf 3 34 x 105 J kg 1 Sw 4186 NCER 2 3 7 C 4 6 7 C 1 2 7 C 3 5 7 C

Two concentric shells have masses M and M and radii R R R R then the force exerted by this system on a particle of mass R R 2 from m if it is placed at a distance centre uestion Type Single Correct Type 1 2 3 4GM m R R 4GM m R R 4GM m R R

18 A flask contains argon and chlorine in the ratio of 2 1 by mass The mixture temperature is 300 K What is ratio of roo mean square speed of molecules of two NCERT Pg 330 gases Atomic mass of argon 39 9 u and molecular mass of chlorine 70 9 u 1 1 33 2 1 55 3 1 77 4 1 66 1 2 In a closed vessel i by adding some gas a molecule of gas When an ideal gas expansion the p enclosure 3 If a gas containe stopped the tem 2021 07 29

What amount of heat must be supplied to 2 x 10 2 kg of nitrogen at room temperature to raise its temperature by 25 C at constant pressure Molecular wt of N2 28 NCERT Pg 321 1 270 5 J 3 370 4 J In changing the state from an equilibrium FIL 2 519 6 J 4 148 3 J of a gas adiabatically state A to another ount of work egual 1 I 2 3 4 10 A orig by VO frr

A car of mass 1200 Kg is moving on a horizontal circular path of radius 80 m If maximum safe speed for the car is 72 km hr The find out the value of coefficient of friction 1 0 5 2 0 6 3 0 4 4 0 3

A Discuss different types of antenna arrays with suitable examples Find the normalized field pattern for the array of two point source with equal Amplitude an out of Phase B What do you understand by the field regions

Sir pls explain it why is it diamagnetic becoz in diamagnet ism field lines are weakly repelled but here in this figure fi eld lines are weakly attracted so isn t it should be parama gnetic pls clear my doubt Given material represents a material which is Paramagnetic Diamagnetic Ferromagnetic

A body moves 6 m north 8 m east and 10 m vertically upwards the resultant displacement of body from its initial position is 1 10 2 m 10 3 2 m 2 10 m 4 20 m

What is smith chart Explain different applications of smith chart 3 Draw the following on the smith chart make tentative smith chart in your copy an lot the values The normalizing impedance is 50 ohm A 50 75j B 10 C 80j D VSWR 2 5 F Min and Max resistance for VSWR 15

Three forces given by vectors 21 21 21 23 and 41 are acting together on a point object at rest The object moves along the direction 1 x axis 3 z axis 2 y axis 4 Object does not move

2 Three forces given by vectors 21 2 21 23 and 41 are acting together on a point object at rest The object moves along the direction 1 x axis 2 y axis 3 z axis 4 Object does not move A body moves 6 m north 8 m east and 10 m vertically unwards the resultant displacement of body from its

Two blocks A and B of masses 2kg and 10 kg respectively are moving in opposite direction collide head on The velocity of A and B just before collison is 10m s and 2m s respectively What is the final velocity if the two blocks stick after colliding

18 An ideal gas is taken through a process where dQ dU dW The specific heat of the ideal gas in this process is dQ heat supplied to the gas dU change in internal energy dW work done by gas 1 C 2 C 3 C 3 2 R

46 A point moves with uniform acceleration and v v denote the average velocities in the three and t3 Which of and v3 successive intervals of time t t2 the following relations is correct a v v V v3 t t t t v V V V3 t t tz c v V V V3 t 1 13 d vz v V V3 t t 13 525 Si

A proton is moving with constant speed towards a conducting ring placed in the same plane along with the path OP The direction of the path of proton ahead of P is O A B C Q 1 Along with A 2 Along with B 3 Along with C 4 Along any path depending upon the speed of the proton