Basic Physics Questions and Answers

Question 30 In the following figure the diodes which are forward biased are A B A B and D C only C and A R and D SV 10V R A C 9 10V R SV 10V R B D R SV

SolveLancer Test Consider these statements i The reason of thermal expansion is asymmetry in potential energy curve ii Coefficient of expansion of invar is very high iii All specific heats found to vary at the low temperatures iv Specific heats of saturated water vapours is negative Select correct option SolveLancer Test a i and ii true b Only ii true c iii and iv true d All are false a b

T A particle starting from the origin 0 0 moves in a straight line in the x y plane Its co ordinates at a later time are 3 3 The path of the particle makes with the x axis an angle of a 30 c 45 e 60 d 0

A steel wire of length 20 cm and uniform cross section 1 mm is tied rigidly at both the ends The temperature of the wire is altered from 40 C to 20 C Coefficient of linear expansion for steel a 1 1 x 10 5 C and Y for steel is 2 0 10 1 N m The change in tension of the wire is a 2 2 106 newton b 16 newton c 8 newton d 44 newton 1 0 X

3 31 In the circuit shown in figure 3 387 the voltmeter is having a resistance 400052 Find the percentage error in reading of this voltmeter AI 5000 300V 40000 V 100002 wwwwww un at

A spring of force constant k is cut into lengths of ratio 1 2 3 They are connected in series and the new force constant is k Then they are connected in parallel and force constant is K Then K K is NEET 2017 1 1 6 2 1 9 3 1 11 4 1 14

I think the correct answer should be 4th option but the b ook says 2nd Please tell me if I am wrong and please expl ain the question properly to me if I am wrong 3 1 7 4 8 4 1 2 4 8 4 8 4 1 A 8 4 units CE B 1 unit D represented by CE on the given number line 24 Which of the following irrational numbers is

View In English An apparatus is connected to an ideal battery as shown in figure For what value of current power delivered to the apparatus will be maximum apparatus 42 Correct Answer 2 Your Answer 1 Status incorrect E RE 2R E 4R information is insufficient Add to Bookmark List A magnet oscillating with rate of 50 jew iew

The variables x and y are related by the equation Sy 2 x 20 where h is a constant Diagram 5 shows the straight line MN obtained by plotting xy against x 0 NO Diagram 5 20 a Express the equation Sy 2 x in linear form which is used to obtain the straight X hown in Diagram 5

2 7 Figure shows a small wheel fixed coaxially on a bigger one of double the radius The system rotates about the common axis The strings supporting A and B do not slip on the wheels If x and y be the distances travelled by A and B in the same time interval then 1 x 2y A B 2 x y

AB and CD are fixed conducting smooth rails placed in a vertical plane and joined by a constant current source at its upper end PQ is a conducting rod which is free to slide on the rails A horizontal uniform magnetic field exists in space as shown If the rod PQ is released from rest then A The rod PQ may move downward with constant acceleration 2 The rod PQ may move upward with constant acceleration 3 The rod will move downward with decreasing acceleration and finally aquire a constant velocity 4 either A or B plo

Energy is stored in the choke coil in the form of 1 Heat 3 Magnetic energy 2 Electric energy 4 Electro magnetic energy 004 H than work done by source to establish a current of 5A in it

Very Short Answer Type Questions 1 According to the New Cartesian Sign Convention for mirrors what sign has been given to the focal leng of 1 a concave mirror ii a convex mirror 2 Which type of mirror has a positive focal length b negative focal length 3 What is the nature of a mirror having a focal length of 10 cm 4 What kind of mirror can have a focal length of 20 cm 5 Complete the following sentence All the distances are measured from the of a spherical mirror 6 What sign ve or ve has been given to the following on the basis of Cartesian Sign Convention a Height of a real image b Height of a virtual image

A particle is confined to move along x axis has a wave function y Cx between x 0 and x 1 0 v 0 elsewhere The value of the constant C is ans 31 2 3 1 2 1 12

2R he two ends of a uniform thin rod of length and of mass 2 kg can move without friction along a fixed vertical circular path of radius R The rod is released fr e vertical position ab Find the force in N exerted by an end of the rod on the path when the rod passes the horizontal position cd

Fig shows a horizontal solenoid connected to a battery and a switch A copper ring is placed on a frictionless track the axis of the ring being along the axis of the solenoid As the switch is closed the ring will T remain stationary 3 move away from the solenoid 100000 HE Ack 2 move towards the solenoid 4 move towards the solenoid or away from it depending on connected to the left end of the solenoid

Example 65 Round off the following numbers as indicated 1 18 35 upto 3 digits iii 18967 upto 3 digits v 248337 upto 3 digits vii 101 55 x 106 upto 4 digits ii 31 325x 105 upto 4 digits ii 143 45 upto 4 digits iv 12 653 upto 3 digits vi 321 135 upto 5 digits

Q 53 Heat produced in a current carrying conducting wire is H I Rt it percentage error in I R and t is 2 4 and 2 respectively then total percentage error in measurement of heat energy a 8 b 15 c 5 d 10 Q 54 The resistance of two resistance wires are R 100 5 2 and R 200 7 are connected in series Find the percentage error in the equivalent resistance of the combination a 8 5 b 12 c 4 d 9

In the crystal structure of Fe O Fe and Fe occupy collectively 1 50 tetrahedral and 50 octahedral voids 2 25 tetrahedral and 75 octahedral voids 3 12 5 tetrahedral and 50 octahedral voids 4 50 tetrahedral and 100 octahedral voids

In which of the following devices the eddy current effect is not used 1 Electric heater 2 Induction furnace 3 Magnetic braking in train 4 Electromagnet A 800 turn coil of effective area 0 05 m is kept perpendicular to a magnetic field 5 105 T When the plane of the c NEET 2015

The mutual inductance between a primary and secondary circuits is 0 5H The resistance of the primary and the seconday circuits are 2002 and 5 2 respectively To generate a current of 0 4 A in the secondary current in the primary must be changed at the rate of 4 0 amp sec 2 16 0 amp sec 3 1 6 amp sec 4 8 0 amp sec are placed near each other on a passing a current of 3 0 A in A the flux linked with A

A circular platform rotates around a vertical axis with angular velocity 1U rad s On the platform is a ball of mass 2 kg attached to the long axis of the platform by a thin rod of length 6 cm 3U F normal force exerted by the ball on the platform in newton Friction is absent

A rectangular coil has 60 turns and its length and width is 20 cm and 10 cm recpectively The coil rotates at a spec 1800 rotation per minute in a uniform magnetic field of 0 5 tesla Then the maximum induced emf will be 3 113 V 2 110 V 1 98 V 4 118 V

Find the value of a for which the vector A is solenoidal A 2xi 2ayj 4zk ans

A thermodynamic system undergoes cyclic process ABCDA as shown in figure The work done by the system in the cycle is NEET 2014 1 RY 2 2P V P 3Po 2Po Pot A V 2Vo V 3 P V 4 zero

on ng 29 The solubility of a specific non volatile salt is high at 25 C If 2gm 4gm and 6gm of the salt added to 100gm at 25 C the vapour pressure X Y Z respectively will follow the order of 1 X Y Z 2 X Y Z 3 Z Y X 4 X Y Z in water at 25 C is 2 105

The number of photons from a light of wavelength 5000 required to do one joule of work is a 1 25 x 1020 m b 1 5 x 1020 m c 2 25 x 1020 m d 2 5 x 1020 m U

33 If a steady current I is flowing element ABC Choose the correct relationship 2r B 1 2 7 1 2 C a VAB 2VBC b Power across BC is 4 times the power across AB c Current densities in AB and BC are equal d Electric field due to current inside AB and BC are

A solid dielectric material has 4 x 1028 atoms per unit volume if it shows an electronic polarizability of 1 5 x 10 40 Fm then the dielectric constant of the material is ans 1 0 1 88 1 2 4 3

A stretched wire emits a fundamental note of 256 Hz Keeping the stretching force constant and reducing the length of wire by 10 cm the fundamental frequency becomes 320 Hz the original length of the wire is Question Type Single Correct Type 1 100 cm 2 50 cm 3 400 cm 200 cm

A vibrator of mass 1 g is acted upon by a restoring force of 104 N m of displacement a retarding force of 4 Ns m and a driving force o cos Wt N The maximum possible amplitude is Select one a 1 02 X 10 1 m b 1 X 10 m c 2 02 X 10 1 d 2 x 103 m

A magnet of magnetic moment 2JT 1 is aligned in the direction of magnetic field of 0 1 T What is the net work done to bring the magnet normal to the magnetic field 0 0 1 J 0 0 2 J 01J

A three level laser emits a light of wavelength 4500 The temperature at which the ratio of the population reduces to half is a 46244 K b 37800 K c 32000 K d 84872 K Hint h 6 63 x 10 34 Joule sec k 1 38 x 10 23 Joule kelvin

An electron and a proton enter region of uniform magnetic field in a direction at right angles to the field with the same kinetic energy They describe circular paths of radius re and Tp respectively Then Question Type Single Correct Type 1 Tep 2 Tep 3 In

What is the relation between temperature of a body and the wavelength of its emitted radiation at its maximum emissive power Select one a none b as temperature of a body increases the wavelength of its emitted radiation decreases at its maximum emissive power c as temperature of a body increases the wavelength of its emitted radiation also increases at its maximum emissive power d as temperature of a body increases the wavelength of its emitted radiation does not change only at its maximum emissive power

3 A time varying magnetic field is present in a cylindrical region of radius R as shown in the figure A positive charge q is taken slowly from P to Q through POQ the magnetic field varies with time as B Bot where Bo is a constant and directed into the plane of the paper If W is the 0 workdone then W P 1 Zero A X XX XX X X X XXXXXX O X XXXX X XXXX 2 Bo

1 mole of H gas is contained in a box of volume V 1 00 m at T 300 K The gas is heated to a temperature of T 3000 K and the gas gets converted to a gas of hydrogen atoms The final pressure vould be considering all gases to be ideal AIIMS 2015 2 2 times the pressure initially 4 20 times the pressure initially of a gas in an adiabatic process is zero and in an isothermal process is infinite 1 same as the pressure initially 310 times the pressure initially T

Q 28 A figure which is of some significance but it does not necessarily denote a certainly is called a significant figure b basic figure c numbering figure d decimal figure Q 29 The mass and volume of a plate are 4 237 kg and 2 51 m 3 respectively Find density of plate in S F a 1 688 kg m3 b 1 69 kg m3c 1 6880 kg m3 d 1 6890 kg m

Find the charge flown through the switch from A to B when it is closed 3 F 5V 6 F 3 F 10V A B 10V 13 F 5V 6 F 6 F

3 If z and errors in determination of A and B are respectively AA and AB then the fractional error in calculation of z is 2 AxB A B 3 AA AB AA AB A B A B AA AB A B AA A AB B AA AB A B

1 Carbohydrates are digested into 2 Cellulose is not 3 Digestion of fat produces 5 4 Liver secretes in nature in man acids and juice which is 5 Grass eating animals like cows and buffaloes are called is the largest gland in human body

ng questions 1 What is a book with a soft paper cover called Paper book 2 Who Who invented the mechanized printing press Johannes Gutenberg 3 At the end of many books you will find a list of the words with page numbers c where the words appear in the book What is this list called 4 What is an introduction to the book by an eminent personality called

If the amplitude of particle executing SHM is doubled then which of the following quantities will be doubled Time period Total energy Angular frequency Maximum acceleration

1 Differentiate the following w r t x 3 i 5x ii tan x sec x iii 6logx x 7

9 A capillary tube of radius r is immersed vertically in a liquid such that liquid rises in it to height h less than the length of the tube Mass of liquid in the capillary tube is m If radius of the capillary tube is increased by 50 then mass of liquid that will rise in the tube is

2 Calculate the current produced in a small germanium plate of area 1 cm and of thickness 0 3 mm when a potential difference of 2V is applied across the faces Given concentration of free electrons in Ge is 2 x 10 m and mobilities of electrons and holes are 0 36 m V s and 0 17 m V s respectively 1 1 3 3 3 3 2 2 3 4 None of these

The relation between Einstein s B coefficient implies Select one a LASING is coherent b LASING is inefficient in natural crystals C All d Stimulated emission rate is equal to stimulated absorption rate

Magnetic field in a cylindrical region is given by B at Find emf across rod AB as shown in figure A O 2R B

What is the shape of the water different containers

Two vectors A and B are inclined at an angle 9 If A B and A B make angles a and B respectively with A then value of tana tan will be 1 2 3 4 2AB sine A B cos 0 2AB sin0 A B cos 0 A sin 0 A B cos 0 B sin 0 A B 2 cos 0