Basic Physics Questions and Answers

A 0 B 60 C 90 D 180 0 If two numerically equal forces P and P acting at a point produce a resultant force of magnitude P itself then the angle between the two original forces is A 0 B 60 C 90 D 120 20 21 A 0 B 60 you 3 and els all B 60 A 0 afeaua fauzir C 90 P you al you i C 90 uzs r D 180 D 120

Molar specific heat of oxygen at consta pressure C 7 2 cal mol C and R 8 3 J mol At constant volume 5 mol of oxygen is heat from 10 C to 20 C the quantity of heat requir is approximately 1 26 cal 3 260 cal 2 360 cal 4 500 cal

Q No 17 In selective assembly A Parts in an assembly can be replaced by a similar part without any further alteration B The parts of any one type are classified into several groups according to size C All the parts are always interchangeable D The size of one of the components is measured accurately and then mating component is made to match with this

30 P Q is a unit vector along X axis If P i j k then what value is Q A i j k B j k C i j k D j k 30 P Q X il le P 1 1 kufu Q B J k D j k A j k C i j k

The density of a solid metal sphere is determined by measuring its mass and its diameter The maximum er ror in the density of the sphere is 100 If the rela tive errors in measuring the mass and the diameter are 6 0 and 1 5 respectively the value of x is

2 2 C 2 9 The angle between the z axis and the vector i j 2k is A 30 B 45 C 60 D 90 29 1 3 k A 30 B B 45 C 0 7 you C 60 D 90

The vectors A and B are such that A BA B then the angle between the two vectors A and B will be A 0 B 60 C 90 D 180 If two numerically equal forces P and P acting C tan 20 19 A B A Bu D tan AB B 60 A 0 you A B C 90 as D 180 a

Q No 18 The advantage of wavelength standard is that it would be possible to repeat measurements to a very high degree of accuracy The wavelength standards can be reproduced to an accuracy of about one part in A 1000 B 109 C 107 D 108

B Two radioactive nuclei P and Q in a given sample decay into a stable nucleus R At time t 0 number of P species are 4 No and that of Q are No Half life of P for conversion to R is 1 minute where as that of Q is 2 minutes Initially there are no nuclei of R present in the sample When number of nuclei of P and Q are equal the number of nuclei of R present in the sample would be a 2 No 9No c 2 b 3 No 5No d 2 Mains 2011

36 2i 2j 2k 9 A B 21 1 1 C 2 2k D None of these Which vector should be added to resultant of 21 4 3k and 31 5j 7k to get a unit vector along positive y axis A si 9j k C 3k B D si 2j 4k 26 21 2j 2k 9 C 21 2k D a 21 4j 3k 431 5j 7k und i su u Gazi and you 414 41 A B 2i j k y all ui ils au A si 9j k B m

08 Find the permitted energies of a stone kept 10 gm kept in a box 10 cm across 09 An excited atom gives up its excess energy by emitting a photon The average neric

Assertion A All conserved quantities are necessarily vectors Reason R The total linear momentum and the total angular momentum of an isolated system which are conserved are vector quantities

15 A metal sphere of diameter D in vacuum has a surface density of charge o The electric field at a point P a distance of 4D from the surface of the sphere is 2 0 H D 1 3 0 81 O 980 4 O 18 O 880

The area or region through which heat transaction occurs is called as O Universe O System Boundry The path obtained from successive states is called as O Feedback Process 1 poin 1 poin

39 White light is mixture of light of wavelength between 400 nm to 700 nm If this light goes through water u 1 33 what will be the limits of the wavelength there a 300 to 525 nm b 600 to 700 nm c 800 to 1000 nm d 1200 to 1400 nm

4 We measure the period of oscillation of a sim pendulum In successive measurements readings turn out to be 2 63 s 2 56 s and 2 42 Calculate the mean absolute error

A cylinder of radius R of thermal conductivity K is surrounded by a cylindrical shell of inner radius R and outer radius 2R made of thermal conductivity K The two ends of the whole system are maintained at two different temperatures T and T T T The system is in steady state and there is no loss of heat across cylinderical surface The electrical thermal conductivity of the system is CG PMT 2015 KCET 2013 Ke a K K K AK K 3K K b K K K K K d K 3K K 2R T K l K T K K Cylinde radius R T 2R I R

At time t 0 magnetic field of 100 Gaussi passing perpendicularly through the are defined by the closed loop shown in the figure If the magnetic field reduces linearly t 500 Gauss in the next 5s then induced EM in the loop is 4cm 12cm 1 36 V 16cm 2 48 V

28 A body of mass 2 5 kg is subjected to the force as shown in figure Find the acceleration of the centre of mass 4N a 2 m s c 3 2 m s 6N 5N 37 1 60 6N b 1 6 m s d None of these

4 2 2 2 A force F 61 2 3k acts on a particle and produces a displacement of s 21 3 xk FS 0 the value of x is A 2 B 1 2 C 2 D S 23 3 111 22 2 1 F 61 2 3 1 1 1 4 2 2 2 i fell 5 21 31 xk eg urine sa s FS 04 dxd you wi X A 2 B 1 2 C 2 D 5

Att 0 a particle is located at x 25 m and has a velocity of 15 m s in the positive x direction The acceleration of the particle varies with time as shown in the diagram What is the velocity of the particle at t 5 0 s 1 15 m s 6 0 5 0 4 0 3 0 2 0 1 0 0 0 1 0 2 0 3 0 4 0 5 0 6 0 2 15 m s 3 30 m s 4 0

40 What will be the moment of inertia of a solid cylinder of mass M and radius R about a line parallel to the axis of the cylinder and on the surface of the cylinder 7 5 a C 2775 MR MR b d 22 3 MR MR

3 What is the angle between vector A and the resultant of 2B and 2A 28 A 0 C tan B tan 1 A B D The vectors A and B are such that 1 D tan t 18 A 2B 2A 2B url ala and A qilyal A 0 C tan 24 7 1 B tan D tan 1 1 A B A B A B

Exact condition of system at any position is called as Surround O State O Process The system in which mass remains constant is called as O Open System 1 poin 1 poin

6 A small block of mass 100 g moves with uniform speed in a horizontal circular groove with vertical side walles of radius 25 cm If the block takes 2 0 s to complete one round then find the normal contact force by the side wall of the groove a 1N b 0 25 N c 0 4 N d 2 N

It is a low grade energy O Heat O work O Enthalpy When mass content in system doesnt perform any motion then workdone is called as O Non flow O Flow Force flow 1 po 1 po

It is found that the force required to row a boat in a river is proportional to the speed of the boat When the speed of the boat is kept v km hr the power expended by the boat engine is 24 horse power What shall be the power in hp required if one wishes to row the boat at a speed 2v km hr GUIRMITT

The acceleration time graph of a particle moving along a straight line is as shown in the figure The time taken by the particle to acquire its initial velocity is a m s 4 2 s 3 s 4 s 8 s 2 t s

A vertical force P 20 lb is applied to the ends of the 2 ft cord AB and spring AC If the spring has an unstretched length of 2 ft determine the forces and angle theta for equilibrium Take k 25 lb ft B 2 ft 2 ft ww k C

Two cells with the same emf E and different internal resistances r and r are re connected in series to an external resistance R The value of R so that the potential difference across the first cell be zero is A rr B 1 1 C 2 1 D 1 1

A potential difference V exists between the ends of a metal wire of length 7 The drift velocity will be doubled if A diameter is doubled B C D current is doubled carrier density is doubled None of the above

Two electric bulbs rated at 25 W 220 V and 100 W 220 V are connected in series across a 220 V voltage source If the 25 W and 100 W bulbs draw powers P1 and P2 respectively then A P1 B P 1 U DP1 CP 9W P 1 4W P 16W 16 W P 9 W 16W P 16W 4W 2

Thermos flask is example of 1 point System O Isolated O Close O Open When Process goes from initial 1 point to final state is called as O Forward Backward O Cyclic

A current of 5A exists in a 10 2 resistance for 4 minutes The number of electrons and charge in coulombs passing through any section of the resistor in this time are A 75 x 75 1020 600C C B 75 x 10 1 1021 600C 1020 1200C 75 x 1020 19

A conducting wire of parabolic shape initially y x2 is moving with velocity V Voi in a non uniform magnetic field B Bo 1 y L kas shown in figure If Vo Bo L and are positive constants and Ap is the potential difference developed between the ends of the wire then the correct statement s is are y L B V Vi L A 40 1 2Bo Vo L for B 0 B 40 remains the same if the parabolic wire is replaced by a straight wire y x initially of length 2 L C 4p is proportional to the length of the wire projected on the y axis

The coefficients of self induction of two coils are L and L To induce an e m f of 2 volt in the coil a change of current of 1A has to be produced in 5 second and 50 ms respectively The ratio of their self inductances L L2 will be A 1 5 LC 100 1 200 1 50 1 B D

When a battery connected across a resistor of 16 voltage across the resistor is 12V When the same battery is connected across a resistor of 10 voltage across it is 11V The internal resistance of the battery in ohms is A B C 10 7 20 7 25 7

A ball moving horizontally with a velocity 2ms strikes the bob of a seconds pendulum at rest If the mass of hte bob is equal to the mass of the ball and the collision in perfectly elastic after collision the bob of hte pendulum will raise to a height of g 10ms

A transverse wave is represented by the equation 2 y yo sin ut x 2 For what value of the maximum particle velocity equal to two times the wave velocity CBSE PMT 1998 JIPMER 2001 02 AFMC 2002 KCET 2007 b 2 3 d 70 a 27yo c y 2

D 4x 6x C 3 The length and breadth of a rectangle are 43 6 0 2 cm and 2 0 1 cm respectively The area of rectangle with error limits is approximately A 12 0 5 cm B 12 1 cm C 12 0 2 cm D 12 2 cm 4 The number of significant figures in 0 06900 D 4x 6x C 6 0 2 cm cons 2 0 1 cm a gel als beg mu B 12 1 cm D 12 2 cm A 12 0 5 cm C 12 0 2 cm cu

A resistance R draws power P when connected to an AC source If an inductance is now placed in series with resis tance such that the impedance of the circuit becomes Z the power drawn will be AIPMT 2015 R 1 P 2 R 2 P R

26 27 A vector is rotated through an angle x 2 the magnitude of new vector is A 2A B A C A 2 D Zero There are two force vectors one of 5N and other of 12N at what angle the two vectors be 26 Ai you beg ud B A D Zero sal 2 well as a Nar A 2A 27 5 12 C A 2

29 30 The minimum number of coplanar vectors of unequal magnitude required to produce a zero resultant is A 2 C 4 B 3 D more than 4 In Figura F equale 29 30 ala A 2 C 4 i yuklaa vas B 3 D 4 sl qu Suspui ca AURIGER

14 The loop shown in figure is rotating with angular velocity around a perpendicular axis passing through O Which of the following graph correctly represent emf developed in the loop as function of 8 0 is shown in diagram Consider anti clockwise current due to ve emf 1 3 emf emf 10 FIN T T F 3 2 2n OK 10 2 emf O emf 4 10 B RIN TC TC 3r 2 2r t

ix A wire of density p unit apart while subjected to an extension T Young s modulus of material of wire is Y then the lowest frequency of transverse vibration in the wire is a 2 YI LVPL c 2L YI pL b d IYI 2L VpL L YI 2 VpL

A conducting bar is pulled with a constant speed v on a smooth conducting rail The region has a steady magnetic field of induction B as shown in the figure If the speed of the bar is doubled then the rate of heat dissipation will remain constant LAX become quarter of the initial value become four fold get doubled B Le D

35 The vectors A and B are such that A B A B then the angle between the two vectors A and B will be A 0 B 60 C 90 D 180 The sum of two forces acting at a point is 36 35 36 C ALB D A B aa A cu B A B A BA A 0 41524 B 60 C 90 D 180 615 42 412ll of 0109 11 2129101

Space between two concentric conducting spheres of radii a and b b a is filled with a medium of resistivity p the resistance between the two spheres will be A B C D 1 1 a b 27 1 1 a b P 1 1 47 a b 2 1 4 2 a

Fig 9 1 shows a bookshelf with two groups of books A and B on it There are six books in each group of books All the books are identical The mass of each book is 0 52 kg 1 3 cm shelf 30 cm 21 cm group A of books 21 cm Fig 9 1 30 cm group B of books 1 3 cm i Explain why the pressure exerted on the shelf by the books in group B is less than the pressure exerted on the shelf by the books in group A

A metal rod of length L 1 m is hinged in vertical plane and it can rotate freely about point O as shown If rod is released from the horizontal position then maximum electric field inside the rod in S I unit comes out to be K 30 find the value of K Assume mass of electron is negligible B XB 2 2 Tesla