Basic Physics Questions and Answers

Three smooth ideal pulleys are connected by a tight string A mass m is attached to the puttey Pa Assume the strings between two pulleys and between the pulley and the support to be vertical B The relation between the magnitudes of acceleration of puttey P a and that of puttey Ps ar is an an 2an an ap 201 Ja

For strong electrolyte variations of molar conductivity with concentration is given by equation A C A C A A AVC 2 A AC

62 For a reaction A B 30 kcal Product the 62 energy of activation of its backward reaction is 50 kcal The energy of activation of its forward reaction is 1 Equal to 50 kcal 2 Greater than 50 kcal 3 Less than 50 kcal 4 Either greater or less than 50 kcal 3 A B 30 kcal fer 350 kcal 1 50 kcal 2 50 kcal 3 50 kcal 4 50 kcal Cr T

Two masses 8 kg and 12 kg are connected at the two ends of a light inextensible string that goes over a frictionless pulley as shown in the figure If all the surfaces are smooth and system is released from rest then net force on the pulley by the string will be g 10 m s 8 kg 48 N 96 N 48 2 N 12 kg

The specific heats C and C of a diatomic gas A are 5 29 J mol K and 22 J mol K respectively Another diatomic gas B has the corresponding values as 30 J mol K and 21 J mol K respectively Which among the following is correct 1 A has one vibrational degree of freedom and B has two vibrational degrees of freedom 2 A has one vibrational degree of freedom and B has zero vibrational degree of freedom 3 A and B both have one vibrational degree of freedom 4 A and B both have two vibrational degrees of freedom 4 4 A us ferongs to a fare a C 29 J molK C 322 J mol Ba 21 J mol K 3 faya 30 J mol K 3 Aff 1 Ata 2 Ata 4 AB pt 3 A 3B

A spherical insulator of radius a is concentric with a conducting spherical shell having inner radius 3 and outer radius 5a as shown in the figure The charge Q is uniformly distributed throughout the volume of the insulator and the net charge on the conductor is Q Q net 3a a Q 5a

If 50 amperes current is passed for 965 seconds to a copper sulphate solution then the mass of copper deposited at cathode is Atomic weight of copper 63 5 31 8 g 15 87 g 63 5 g 7 93 g

In the circuit given below the resultant resistance across the points A and B is ABRIR URINA Garte A R 6 R wwww R R www R www R www R

Two balls are dropped from different heights at 7 different instants Second ball is dropped after 2 seconds of dropping the first ball If both balls reach the ground simultaneously after 5 seconds of dropping the first ball then the difference between the initial heights of the two balls will be g 9 8m s 1 58 8 m 2 78 4 m 3 98 0 m 4 117 6 m f 2 tam g 9 8m s 1 58 8 m 2 78 4 m 3 98 0 m 4 1176m

Topic Syllabus 1 2 Two particles of same mass M are moving in a 1 circle of radius R because of their mutual gravitational forces Their speed would be 1 2R V GM 3 GM 51 D GM V2R 4 4GM Tam greater galeri R are 1 1 2R V GM 1 GM R 3 7 4 GM 2R 4GM R

A solid sphere rolls down two different inclined 45 planes of the same height but of different inclinations 1 in both cases the speeds and time of descent will be same 2 the speeds will be same but time of descent will be different 3 the speeds will be different but time of descent will be same 4 speeds and time of descent both will be different z aig an fum gert at for tel 1 ff 3 and den 444 244 2 Buffang find a form aru 3 ff for f 3r an 444 4417 arn 4 en and a fu

Q1 A concave mirror is used for image formation for different positions of an object What inferences can be drawn about the following when the object is placed at a distance of 10 cm from the pole of the mirror of focal length 15 cm a Position of the image b Size of the image c Nature of the image Draw a labelled ray diagram to justify your inferences

10 The velocity time graph of a body is The displacement v m s 2 1 T covered by body in 5 s is 1 2 supe 3 4 12 20 da no rbaud 19 0102 2 s Jaso 30 ogol 5 rl 1 2m 2 4 m 3 3 mall pieste 4 1 movom eking A

In function F av sin t F denotes force v velocity and t time The dimensional formula of a is same as dimensional formula of acceleration due to gravity O work done O atmospheric pressure

In phase diagram shown the point Q corresponds to the triple point of water The regions 1 II and II respectively correspond to phases Q 3 11 a Liquid solid vapour b Solid liquid vapour c Liquid vapour solid d Solid vapour liquid

7 3 0 51 4 0 30 A disc is rotating with an angular velocity A 17 constant retarding torque is applied on it to stop the disc The angular velocity becomes to 2 after n rotations How many more rotations will it make before coming to rest 2 2n 1 n 3 0 51 4 0 30 E 00 1 n a ad squa feed started a faut saten der gerne 54 T 130 at f 2 2n

Solution X turns red in the presence of blue litmus solution The pH of the solution X is approximately FX Buffald Rafa GXpH A 8 B 2

A Newtonian fluid fills the clearance between a 34 shaft and a sleeve When a force of 800 is applies to the shaft parallel to the sleeve the shaft attains a speed of 2 cm s If a force of 2 4 kN is applied instead the shaft would move with a speed of 1 2 cm s 3 6 cm s 2 15 cm s 4 None of these Two blocks one of mass A HONEY 1 kg and another 35 LE 2 FREE 20142 30 yas and an ata fena red and an THER THIRT GIG a 2 cm and af ved ad CHORD GIANT 1 2 cm ST 3 6 cm s 2 4 k 2 15 cm s 4 I ay for us and 1 kg gut an

6 A bullet of mass 0 02 kg travelling horizontally 16 with velocity 250 ms strikes a block of wood of mass 0 23 kg with rest on a rough horizontal surface After the impact the block and Bullet move together and come to rest after travelling a distance of 40 m The coefficient of sliding friction of the rough surface is g 9 8 ms 1 0 75 2 0 61 3 0 51 4 0 30 0 02 kg eft 250 ms 0 23 kg erst sua fugiat fara ye fan 1 0 75 2 0 61 3 0 51 4 0 30 40 m de g 9 8 ms

Kinetic energy of a particle depends on the squa of speed of the particle If error in measurement speed is 40 then error in the measurement kinetic energy will be 1 80 3 96 2 40 4 120

Question No 13 110 volts rms is applied across a series circuit having resistance 11 and impedance 22 Q The power consumed is Options 366 W 550 W 1100 W

5 Two s Complement Representation Show your work a Convert the 8 bit Two s Complement binary number 1001 11012 to decimal b Convert the 8 bit Two s Complement binary number 0111 1010 to decimal

An electron is moving in the South direction in a region of uniform magnetic field which is directed into the plane of paper The direction of force experienced by the electron is towards Uch Sac fa Add Ych UHF Frachtu ta maha I SMAC A GRI ud fchu nad farm B East 32 West North

A point charge is situated at an axial point of a small electric dipole at a large distance from it The charge experiences a force F If the distance of the charge is doubled the force acting on the charge will become a 2F b F 2 c F 4 The electric flux emerging out from IC charge is CBSE 2020 55 1 3 d F 8 ICBSE 2020 55 3 1

Energy of electron in second orbit of He is 1 6 80 eV 2 13 6 eV 3 27 20 eV 4 54 4 eV 49 He 2nd 1 6 80 eV 3 27 20 eV gra 2 13 6 eV 4 54 4 eV

When a wave traverse in a medium the displacement of a particle located at x at a time t is given by y asin bt cx where a b and care constants of the wave which of the following is a quantity with dimensions

Which of the following statement is incorrect Magnetic field is a quantity that has both direction and magnitude a Magnetic field lines are closed curves are a stat The relative strength of the magnetic field is shown by the degree of closeness

c spheres us poorly m equals ifference from an erval At Fer the ature is the 2 56 figure 3 402 shows two lamps L and L in series and connected across 100V battery Find the power consumed by each lamp 100 200V 100W oo L 200V 200W 00 100V Figure 3 402 L2

If ix x jx xj kx k 8 ix xi j j k k then 1 u is a unit vector 2 i j k 3 u 2a 4 u 8 i j k FX 1 2 i j k 3 25 4 8 i j k

A hollow sphere of inner radius R and outer radius 2R is made of a material of thermal conductivity K It is surrounded by another hollow sphere of inner radius 2R and outer radius 3R made of same material of thermal conductivity K The inside of smaller sphere is maintained at 0 C and the outside of bigger sphere at 100 C The system is in steady state The temperature of the interface will be A 50 C B 70 C D 45 C C 75 C s C

A ball is suspended from the top of a cart by a string of length 1 0m The cart and the ball are initially moving to the right at constant speed V as shown in figure 1 The cart comes to rest after colliding and sticking to a fixed bumper as in figure 2 The suspended ball swings through a maximum angle 60 The initial speed V is take g 10 m s V A 10 m s Figure 1 B 2 5 m s Bumper C 5 2 m s Figure 2 Bumper D 4 m s

40 In the circuit shown ratio of capacitors is C C1 4 3 and terminal voltage of the battery connected at the left end is Vo What should be terminal voltage of the battery connected at the right most end so that the potentials of nodes 1 2 3 4 5 and 6 be in a geometric progression 1 Vo C C HI 2 C C HI 3 C C 4 HH C C HI 5 C C HH 6 C

pg 2pg A lift of mass 100 kg starts moving from rest in 13 100 kg farve fa fra downward direction figure shows the variation of speed of the lift T T T stands for the tension in the rope from zero to two seconds two to six seconds six to seven seconds respectively then v 4m s 6 t sec 1 T T T 1 1 1 2 T T T 4 5 7 3 T T T 6 5 3 4 T T T 6 5 6 Two blocks A and B of masses 4 m and m 14 7 aun T tar PB sferz T T C v 4m s 2266 A 1 T T T 1 1 1 2 T T T 4 5 7 3 T T T 6 5 3 4 T T T 6 5 6 t sec 4 m

If the radius of a coil is halved and the number of turns doubled then the magnetic field at the centre of the coil for the same current will A B get doubled get halved become 4 times remain unchanged

Two masses A and B connected with an inextensible string of ength I lie on a smooth A2m horizontal plane A is given a velocity of v m s along the ground perpendi cular to line AB as shown in figure Find the tension in string during their subsequent motion A mv B 1 C 2mv Bm D 2mv 31 4mv 1

Given that the force of interest is answer to five decimal places t find the effective rate of discount in percent for the ninth year Round y 1 1

A smooth rod PQ is rotated in a horizontal plane about its mid point M which is h 0 1 m vertically below a fixed point A at a constant angular velocity 14 rad s A light elastic string of natural length 0 1 m with elastic constant 1 47 Nicm has one end fixed at A and its other end attached to a ring of mass m 0 3 kg which is free to slide along the rod When the ring is stationary relative to rod then find cosine of angle made by string with vertical A IM

4 u 8 i j k A wire extends by t mm when a weight W is 9 hanged from it If the wire passes through the pulley and a weight W is attached at one end whereas 3W is attached at the other end then the extension in mm of the wire is 1 2 20 3 20 3 4 30 2 4 u 8 1 j k waar l mm far gant and mm 1 3 20 3 for na fare fort a fe 2 20 4 30 2 fata

A and B are concentric conducting spheres A is positively charged while B is earthed as shown in the figure then a A and B both have same charge densities The electric field between A and B is zero The potential inside A is zero Inside the sphere A the electric potential is constant

A point sound generating source of power 6 5 milli watts is placed at the centre of the hollow cylinder of length 24cm and it s radius of cross section 5cm Then the power passing through the lateral surface of the cylinder in milli watts is

Projection on inclined plane 25 A ball is projected from the foot of an incline plane of inclination 30 at an angle 60 with the horizontal with velocity 20 3 m s The time after which the ball will strike the plane is 1 2 s 3 6 s 2 4 s 4 8 s

A car having fixed quantity of fuel moves on a straight horizontal road with constant speed Air resistance acting on it is given as F 0 0 0 0 Speed for maximum range is 1 4 2 4 Speed for maximum range is B 2a Speed for maximum time of travel is Speed for maximum time of travel is 1 4 3 3a 3 40 1 4 1 4 3 v where a and B are constants and v is speed of car

27 The equivalent resistance of the network shown in the figure across the points O and A is resistance of each branch of the octagon is ro 1 2 3 69 49 49 69 69 149 ro A 112

sF A car having fixed quantity of fuel moves on a straight horizontal road with constant speed Air resistance acting on it is given as 0 Speed for maximum range is Speed for maximum range is 1 4 3 2a 8 Speed for maximum time of travel is 1 4 Speed for maximum time of travel is 3 3a 3 4x 1 4 1 4 av 1 2 v where a and B are constants and v is speed of car

0 What is the length of the image of the rod in mirror according to the observer in air refractive index of the liquid is A B L L Eye C Lut L D None of thang

3 Electron excess defect 4 Impurity defect For the coagulation of 100 ml of ferric hydroxide 54 sol 10 ml of 0 5 M KCI is required What is the coagulation value of KCI 1 5 2 10 3 100 4 50 3 gia sufuran 4 3 100 ml 10 ml 0 5 M KC m 1 5 2 10 game 3 100 KC 4 50 fa

X Q 14 Three vectors A B and C 0 1 add up to zero Find which is false O O O a A B C is not zero unless B C are parallel X b A B C is not zero unless B C are parallel c If A B C define a plane A B C is in that plane d A B C A B C C 2 A 2 B 2

The point of this question is to compare rest energy and kinetic energy at high speeds An alpha particle a helium nucleus is moving at a speed of 0 9990 times the speed of light Its mass is 6 40 x 10 27 kg Question What is its kinetic energy

Y O If u a bj and v pi qj O orientation of two vectors u and v in the XY plane Which of the following is correct O X a a and p are positive while b and q are negative b a p and b are positive while q is negative c a q and b are positive while p is negative d a b p and q are all positive X

Lower end of a uniform inextensible rope of length 4m and having mass 2kg is attached to a block which is at rest due to sufficient friction Tangent at lower end is horizontal F Upper end is pulled with hand by a force F tangentially so that whole system is in equilibrium Take tan 0 5 26 5 List l List II P Force applied by hand in N Q Friction acting on block in N R Angle made by F with horizontal in degree S Tension at half the height of hand in N OP 4 Q 3 R 5 S 2 2m OP 20 3 R 5 S 1 1 37 2 3 20 4 25 5 53 15