Physics Questions

12 A spot light source is fixed 4 m from the vertical wall and is rotating at rate 1 rad s The spot image moves horizontally on the wall The speed of the spot on the wall when spot light makes angle of 45 with the wall is The line joining spot source and image is in horizontal plane 1 2 m s 2 3 m s 3 8 m s 4 1 m s 217 If u to bo

A person cannot see objects distinctly at a distance less than 1 m The power of the spectacles that he use in order to read a paper at a distance of 0 25 m is O 4D O 0 5 D O 3D O 3D

Transfer function of following system is R s G G G1 G2 1 G1G3 G1G4 G2G3 G2G4 G G1G2 G3G4 1 G1G3 G1G4 G2G3 G2G4 G1 G2 1 G1G3 G1G4 G2G3 G2G4 GA G1 G2 G3 G4 1 G1G3 G1G4 G2G3 G2G4 C s

50 A particle of mass 6 kg moves with an of v 81 81 m s A constant velocit force F 301 N is applied on the particle Initially th particle was at 0 0 The x coordinate of the partic when its y coordinate again becomes zero is give by 1 6 0 m 3 8 m 2 12 8 max 0

3 127 A body A is projected vertically upwards Another body B of same mass is projected at an angle of 60 with the horizontal If both the bodies attain same maximum height then ratio of initial kinetic energy of body A to that of body B is 3 1 E 4 X 1 3 To ei led ort 2 4 3 2 1 2 mag2 2 Imvz Hoa A ist 280

9 A non conducting ring of radius R has uniformly distributed positive charge Q A small part of ring of length d is removed d R The electric field at the centre of ring will be 1 Directed towards the gap inversly porportional to R 2 Directed towards the gap inversly porportional to R 3 Directed away from the gap inversly porportional to R 4 Di

An object is placed at a distance of 20 cm from a co axial combination of two lenses A and B The combination of the lenses forms a real image which is four times the size of the object If lens B is concave with a focal length of 48 cm then what is the nature and focal length of lens A convex 12 cm convex 6 cm O O concave 12 cm convex 18 cm

An observer is moving with constant towards a fixed source of sound As per Doppler s effect the variation of frequency fobserved with time t is best represented by 1 3 F f 2 4 P

Two charges of equal magnitudes and kept at a distance r from each other exert a force F on each other If eac of the charges are doubled and distance between them is made one third of initial distance then the new force acting on each charge is OF 8 O 36 F O 6 F O F 16

1 25 minute 3 12 minute 4 12 5 minute 12 In a house individual power of two elements are 100 W and 150 W Effective power of their series combination will be 1 120 W 3 50 W 2 75 W 4 60 W of power 60 and 100 W respectively each rated 110 V are connected in series with the supply

Two persons starts moving with same speed 5 m s One in the direction of north and other is in the direction of east as in figure Angular velocity of A with respect to B is A Gus This lav pritrk 10 m ledas 8 00 4 0 6 m s sunk S B WABE WA heal ons latehingg 2 Zem 5x10 of

4 Inc 76 Stress vs strain graph for two different wires A and Bis given If Y and Y are Young s modulus of material A B then Stress 1 YA 3 YB 3 Y 3Y R niboo 15 30 A B Strain 2 3 YA YB 4 3Y YR B

38 It is raining at 20 m s in still air Now a wind starts blowing with speed 10 m s in north direction If a cyclist starts moving at 10 m s in south direction then the apparent velocity of rain with respect to cyclist is sqa rtw balosing balosiong al altbetong A Ter 1 20 m s 2 20 2 m s 19306 nee 3 10 5 m seshorer 4 30 m semits

A 10 m long steel wire has mass of 5 g If wire is under a tension of 80 N the speed of transverse wave on the wire is O 400 ms 1 500 ms 1 O 300 ms 1 O 900 ms 1

A hollow copper tube of 10 m length has an external diameter of 20 cm and its walls are 10 mm thick Th specific resistance of copper is 1 7 x 10 8 Q m The resistance of the copper tube is approximately O 5 6 x 10 30 O 5 55 10 50 O 2 8 10 Q 2 85 10 50

Two dots are 1 mm apart on a screen They are seen by eye of pupil radius 1 5 mm The maximum distance at which these dots are just resolved by the eye if light of wavelength 500 nm is used 1 1 m 2 5 m 4 6 m 3 3 m

Three light bulbs having the ratings 40 W 200 V 50 W 200 V and 100 W 200 V are connected to a 60 supply in series What is the possible case which can happen as the supply is switched on O 40 W bulb will not fuse 100 W bulb will not fuse O All the three bulbs will light with their rate powers O Only 50 W bulb will fuse

30 A solid cylinder of radius 10 cm and length 1m clamped from its one end is twisted through angle 0 4 rad by applying torque at other free end The shear strain developed in cylinder will be 2 0 8 4 0 04 1 0 2 3 0 02 2 bao longth

30 A boy runs on a circular track of radius R in km 27 C TR 2 and then R km h in anticlockwise sense for 1 h The magnitude of his displacement will be nish with speed of om s bra km h in clockwise sense for 3 h TR 2 nivit encloones as moit er yd 3rR mod arth to 3 1 R 2 2 begooib ai dmod A 25 Mainosher 4 2R 8

In the given figure AC is a current element of strength 0 4 A m placed at the centre of a circle of radius 10 cm Calculate magnetic field induction at the points P Q M and N M N CA 60 P Magnetic field B Boxk exists in a region of space A particle of specific charge a charge per unit mass enters this region of space Its velocity and position of time t 0 are v voi and 0 0 0 Find the maximum x displacement of the particle

When a projectile is fired at an angle 8 w r t horizontal with velocity u then its vertical component till body reaches its maximum height Remains same Goes on increasing with height Goes on decreasing with height First increases then decreases with height

0 A particle is projected from the origin with velocity 41 91 m s The acceleration in the region is constant and 10 m s The magnitude of CWT Cor velocity after one second is TO D 1 8 m s 2 15 m s 3 17 m s 4 27 m s w 11s att adt b du vd nevis ierit to sebutingem

10 Figure shows graph between and V for two conductors A and B Their respective resistances are in the ratio A V Z JK V R 1 1 1 3 3 1 30 30 A B V V 2 1 3 4 1 2 ton 30 160 1 5

The absolute temperature of a gas is increased to 16 times of origina temperature The root mean square speed of its molecule becomes Twice O Four times O One fourth O Halved

A plane boundary separates two transparent media A and B The speed of light in medium A is 1 5 x 108 m s and in medium B is 2 0 x 108 ms The critical angle for which ray of light going from A to B gets totally internally reflected is O sin sin O sin O sin 1

24 The instant at which a bulb is switched on its power is maximum then it decreases to a steady value Explain

20 A particle is thrown from ground with a speed 20 m s at an angle 60 above horizontal Average velocity over its entire journey just before hitting the ground is 1 10 m s 3 Zero 2 20 m s 7 4 15 m s

A ray of light which is initially horizontal passes through a glass cylinder of radius R as shown in the figure given below Taking refractive index of air nair 1 based on the geometry of the light ray s path as shown in figure find index of refraction of the glass nglass horizontal ray R 60 C nglass nar 1 00 R Horizontal

Which of the following is not a property of magnetic lines of force O The tangent at any point on the magnetic lines of force gives the direction of the magnetic field at that point Magnetic lines of force are crowded where the magnetic field is strong and far from each other where field is weak O No two magnetic lines of force can intersect each other O They are closed continuous curves They start from south pole and end on north pole outside the body of a bar magnet

A thin uniform rod of length I and mass m is uniformly charged with a total charge q The rod is rotated about a point at a distance from 1 3 midpoint of the rod The magnitude of the magnetic moment of the rod if the angular velocity is is 1 2 3 90 72 7290 590 90 36 Zaml

A charged particle of mass m and charge q enters a magnetic field region with velocity v perpendicul magnetic field B The change in kinetic energy of particle after it travels a distance d is Ignore gravity AKE 2qy Bd AKE zero OAKE 2qvBd O AKE qyBd

small balls each of mass each of them on are swo light insulating Two q through length I expression of the m and char Static suspended string of for string from a point angle o made by any with vertical couilibrium Find the q

140 A body of mass 2 kg is projected at a speed of 20 m s from a pillar of height 40 m at an angle of 30 with the horizontal in upward direction Speed with which it will hit the ground is 2 20 3 m s 4 40 m s BUCO 1 30 m s nsini 3 25 m s

the capacitor at steady state is R 1 2 3 R CE 9 2CE 9 CE 3 network shown the energy stored in OCE R wwww C HHH E R www R www of n n n x ve l an n 1 n

A person aiming to reach exactly opposite point on the bank of river is swimming at speed of 6 km h at an angle of 150 with the direction of flow of water The speed of water in stream is 5 2 km h 1 4 6 km h 1 3 km h 1 STIME 2 km h 1

4 A ball of mass m moving with a speed u undergoes a head on elastic collision with a ball of mass nm initially at rest The fraction of the incident energy transferred to the heavier ball is 1 n 1 n 2n 3 1 n 2 n 1 n 4n 4 1 n

A dog of mass m is walking on a pivoted disc of radius R and mass M in a circle of radius R 2 with an angular frequency n the disc will revolve in opposite direction with frequency Y FLA 22 1 izt 1 3 mn M 2mn M R 2 2 AL 42 FXLX 79 mn 2M e d 2 FX 2 L X 2Mn 4 M 5am and b 20cm If the M I of the

5 If a source of frequency n moving with velocity crosses a stationary observer then the change in the frequency of sound heard by the observer will be velocity of sound V 1 3 2nVv V v 2nVv V V 2 4 2nVv V v 2nVv V V

One mole of an ideal gas expands from initial state 27 Vo to final state To 2V The process of expansion Work done by the gas TOV 3T is given by T during the expansion is 7 temperature V volume 1 RT In2 2 3RT In2 3 RT 31n2 1 4 To Vo 0

A charge of 10 C flows from point A to B Work done on charge is 8 x 10 3 J What is the potential of point A if potential of point B is VB 1000 volt 50 V O 150 V O 100 V O 200 V

3 0 3 If and E are current density and electric field respectively inside a current carrying conductor then corred relation is 1 GE 3 j 0 2 jxE 0 4 All of these

59 In the first stage of a two stage Carnot engine energy Q is absorbed at temperature T and energy Q is expelled as heat at intermediate temperature T The second stage absorbs the energy Q and expels energy Q at a still lower temperature T3 If the work output of both the stages is same then T is equal to 2 1 T T3 2 3 T T3 2 4 T T3 2 T T3 2

which of the following statement is correct P The addition of pole to an OLTF pulls the root locus to the right Q The addition of pole to an OLTF pulls the root locus to the Left R The addition of zero to an OLTF pulls the root locus to the right S The addition of zero to an OLTF pulls the root locus to the Left P S Q R PR

A force F is applied to a dumbbell kept on smooth surface 1 for a time interval t first as in figure i and then as in figure ii The final speed of centre of mass in figure i is v and figure ii is V V2 then E i Y 2x0 3 1 5X10 F m UFULI 1 1 nx 1 889 1 V V 2 v v 3 4 Depends on the rotational inertia of the dumbbell 1 SX onal 99 1

Hint P VI 29 Three equal resistors connected in series across a source of EMF together dissipate 10 W of power What would be the power dissipated if the same resistors are connected in parallel across the same source of EMF 1 25 W 3 45 W Hint P parallel n n 3 Pe series 2 80 W 4 90 W

A long solenoid is fabricated by closely winding a wire of thickness 0 5 mm over a cylindrical nonmagnetic frame so that the successive turns nearly touch each other What would be the magnetic field B at the centre of the solenoid if it carries a current of 2 5 A O 10 T O4 x 10 T O2TX 10 T O None of these

When displacement of a particle executing SHM is one fourth of its amplitude Chen what fraction of total energy is kinetic energy 15 16 0 1

Some of the statements regarding ethanol and ethanoic acid are given below i Ethanoic acid has a pungent smell while ethanol has a pleasant smell ii Ethanoic acid gives litmus test but ethanol does not give litmus test iii The boiling point of ethanoic acid is higher than that of ethanol iv Ethanol can react with NaOH but ethanoic acid doesn t Which statement is correct O i and iv only Oii and iv only Oi ii iii only Oi ii iii and iv

133 If the block is pulled by the rope moving wit speed v as shown then the horizontal velocity the block is iw nwoint ai eloinsq Ba 1 V 3 V m O V VA V250 9 11 4 em than it has to 2 v cose mart mes 5 1

7 A particle moving towards east with a velocity of 20 m s In 20 s it changes its velocity to 60 north of east its average acceleration will be 2 2 m s 4 0 5 m s 1 3 m s 3 1 m s