Physics Questions

If magnitude of dispersive power of two lens are 6 0 024 and 0 036 then focal length be for aberration free combination 2 30 cm 45 cm 4 20 cm 35 cm 1 30 cm 40 cm 3 10 cm 30 cm atau fac d 0 02 3IT 0 036 370 KHI PH I K T KHI I 1 30 cm 40 cm 3 10 cm 30 cm 2 30 cm 45 cm 4 20 cm 35 cm

A zener diode having breakdown voltage equal to 10V is used in a voltage regulator circuit shown in figure The current flow the diode is A B C 10 mA 5 mA 15 mA 20002 ww ISV OV 1ks

A converging beam of light is incident on a concave lens of focal length 20 cm In the absence of lens the beam converges at a point 10 cm behind the lens At what point the beam will converge diverge after refraction Converges to 5 cm behind the lens Diverges to 10 cm behind the lens Converges to 6 cm behind the lens Converges to 20 cm behind the lens

or more than one choice correct type Questions Consider the condition shown in the figure Pulley is massless and frictionless springs are mass Both the blocks are released with the springs in their natural lengths Choose the correct options MAMAMAY A Maximum elongation in the spring S is B Maximum elongation in the spring S is Th www m 4m m g K m m 4m m g K m m C If m m both the blocks will come to instantaneous rest simultaneously D If K K both the blocks will come to instantaneous rest simultaneously

If a body covers first half of its journey with uniform speed v and the second hal of the journey with uniform speed v the the average speed is 1 2 1 V V 2 V V2 2 2 V V2 1 V V2 1 4 V V

ALLEN 4 The minimum energy required to launch a m kg 14 ma satellite from the earth s surface in circular orbit at an altitude 2R where R is the radius of earth is 1 mgR 2 mgR 4 mgR 5 3 mgR f f far and Raffront 1 mgR 3 mgR 2 mgR 4 mgR

A shortsighted person can read a book clearly at 8 a distance 10 cm from the eyes Find the lens required to read the book kept at 60 cm 1 f 30 cm 2 f 30 cm 3 f 12 cm 4 f 12 cm A beam of light is converging towards a point I on 9 fffff 10 cm fer for 1 f 30 cm 3 f 12 cm a 60 cm any 2 f 30 cm 4 f 12 cm far far fund a

The focal length of objective lens of astronomical telescope is 50 cm and tube length is 55 cm when final image is obtained at infinity The angular magnification of telescope will be O 11 O 10 O45 60

The focal length of eyepiece and objective lens of astronomical telescope are 2 5 cm and 50 cm respectively Then maximum angular magnificati will be O 20 O 22 0 1 O 220

Q23 A circular disc of mass M and radius R is rotating with an angular velocity w about an axis passing through its centre and perpendicular to the plane of the disc A small point like part of mass m detaches from the rim of the disc and continues to move with same angular speed The angular velocity of remaining disc just after detaching will become a b M 2m M m M 2m M m d M 2m c M M m 0 0 M 2m M m e w 0

Which of the following gates will have an output of 1 D 1 0 0 1 0 1 0 1 A

3 10cm 4 2 5cm A body of mass m is situated at distance 4R 13 above the Earth s surface where R is the radius of Earth how much minimum energy given to be the body so that it may escape 2 2mg mgR 16 1 mgR mgR 3 5 3 10cm 4 2 5cm me and years fear and R qoffroa atd ant fa 1 3 mgR mgR 5 2 2mg mgR 4 16

Q 1 Q 30 Carry ONE mark each The two vectors P i q i j 2 are a related by a rotation c related by an inversion A 3 x 3 matrix has b related by a reflection through the xy pla d not linearly independent

The drawing shows a top view of a frictionless horizontal surface where there are two springs with particles of mass m and m attached to them Each spring has a spring constant of 1200 N m The particles are pulled to the right and then released from the positions shown in the drawing How much time passes before the particles are side by side for the first time na at x 0m if m 3 kg and m 27 kg If time is sec fill n in OMR sheet 80 Immo m mm m mo m Position of unstrained spring x 0

The resistance of a coil for dc is R ohms When connected to ac supply the total resistance offered by circuit to ac current A Will remain same B Will increase C Will decrease D Will be zero Correct Answer

A 3 x 3 matrix has eigenvalues 0 2 i and 2 i Which one of the following statements is correct a The matrix is Hermitian b The matrix is unitary c The inverse of the matrix exists d The determinant of the matrix is zero The 1 2

The figure shows a transparent sphere of radius R and refractive index u An object O is placed at a distance x from the pole of the first surface so that a real image is formed at the pole of the exactly opposite surface Air X A If x 2R then the value of u is 3 C If x 2R then the value of u is 2 2R B If x then the value of u is 2 D If x then the value of u is 3

If a circular hole of radius R 2 is removed from semicircular disc as shown find the moment of inertia about AB of the remaining body Use mass of semicircular disc as m before removal A 5mR 32 B 3mR 32 C B R 3mR 32 D mR 32

3 6 mH 31 Find potential difference between A and C if potential difference between A and B at a certain instant is 12 V 1 12 V 3 36 V 0000000 6 H B ooooooo 4 H 0000000 12 H 2 24 V 4 Zero A

The flatbed truck starts from rest on a road whose constant radius of curvature is 30 m and whose bank angle is 10 If the constant forward acceleration of the truck is 2 m s2 determine the time t after the start of motion at which the crate on the bed begins to slide The coefficient of static friction between the crate and truck bed is us 0 3 and the truck motion occurs in a horizontal plane 10

Ans a 1 0 m s b 50 m s c 24 5 J 21 A smooth sphere mass 10 kg rolls on a smooth curved surface from the point A with a speed of 10 m s The sphere reaches the point D passing through point B Find a the total energy of the A 20m C 10m E B 13m sphere at the point A b the kinetic energy and the

A capacitor of capacitance 1 mF originally charged to a potential difference of 10 V is connected to an inductor of inductance L If the maximum current in the circuit is 10A find the value of inductance L in mH Assume inductor to be ideal 10V L C000009 1 mF

A ball of mass 1 kg bounces against the smooth floor as shown in the figure The approaching velocity is 25 m s and the velocity after hitting the ground is 15 2 m s then 1kg 25m s 53 50 15 2 m s A 0 has value 4 B impulse exerted on the ball is 5 5 3 2 Ns C impulse exerted on the ball is 35 Ns D Total Linear momentum of the ball is conserved

mass 25 kg rests on a horizontal floor u 0 2 It is attached by a 5m long horizontal rope to a peg fixed on floor The block is pushed along the ground with an initial velocity of 10 m s so that it moves in a circle around the peg Choose the correct statement s A Magnitude of tangential acceleration of the block is 2 m s B Speed of the block at time t 1 sec is 8 m s C Time when tension in rope becomes zero is 5 sec D Friction force acts towards centre of the circle 5m

Identify the correct statement regarding power MOSFET You can select multiple correct answers MOSFET is a unipolar voltage controlled three terminal device The MOSFET has higher switching losses than that of a BJT The gate circuit impedance of MOSFET is higher than that of a BJT MOSFET is a bipolar current controlled two terminal device

A particle with an initial velocity vi enters a region with an electric field Ej and a magnetic field Bj The trajectory of the particle will a be an ellipse c be a helix with constant pitch b be a cycloid d not be confined to any plane

Using ampere s circuital law we can find A Magnetic field due to a long isolated current carrying straight wire B Magnetic field inside a long current carrying solonoid C Magnetic field due to a current carrying circular loop at points on its ax D Magnetic field due to a finite current carrying wire

Obtain the approximate force in MN required to punch a 20 mm diameter hole in a plate that is 50 mm thick Use shear strength as 350 MN m and 22 7 6 10 m

TOO A simple pendulum is suspended in a uniform electric field E as shown in the figure What will be its period if its length Charge on the bob of pendulum is q and mass is m is Ans T 2 1 2 9 E 28qE cose 8 2 m m

A solid hemisphere rests in equilibrium on a rough ground and against a smooth wall The curved surface touches the wall and the ground The angle of inclination of the circular base to the horizontal is 30 Find minimum coefficient of friction required between ground and hemisphere Fill 32 in OMR sheet

The figure represents a voltage regulator circuit using a Zener diode The breakdown voltage of the Zener diode is 6 V and the load resistance is R 4 k2 The series resistance of the circuit is R 1k2 If the battery voltage V varies from 8V to 16V what are the minimum and maximum values of the current through Zener diode Main 2019 10 April II 8 v to 160 VB 6 a 1 5 mA 8 5 mA 05 25mA 3 K10 i x1 R Gu R 4ku b 1 mA 8 5 mA 3 05

A ball is projected from point O on the ground It hits a smooth vertical wall AB at a height h and rebounds elastically The ball finally lands at a point C on the ground During the course of motion the maximum height attained by the ball is H E if OA 02 27134 OC a Find the ratio b Find the magnitude of average acceleration of the projectile for its entire course of flight if it was projected at an angle of 45 to the

The maximum value of anode current which it must attain during turn on process to maintain conduction when gate pulse is removed The minimum value of anode current which it must attain during turn on process to O maintain conduction when gate pulse is removed Identify the correct statements about fast recovery diode You can select multiple correct answers Current rating vary from 1 A to several thousand amperes Voltage rating is maximum up to 100v The diode with low reverse recovery time Used in line frequency rectifiers Select correct statements for gate triggering You can select multiple correct answers

dv dt triggering of SCR IS SCR is turn off by changing the forward bias voltage with respect to time O Anode cathode forward voltage is increased O None of the mentioned SCR is turn on by changing the forward bias voltage with respect to time

that is 50 mm thick Use shear strength as 350 MN m and 22 7 A horizontal pipe has a cross section of 10 cm in one region and of 5 cm in another Th water velocity at the first is 5 ms and the pressure in the second is 2 x 105 Nm 2 Th pressure of water in 1st region is given by 237 5 x 10 Pa Then the value of a is

Two balls are dropped from the top of a high tower wi time interval of t second where to is smaller than the time taken by the first ball to reach the floor which is perfectly inelastic The distance S between the two balls plotted against the time lapse t from the instant of dropping the second ball is best represented by

Standing waves are produced on a stretched string of length L with fixed ends When there is a node at a distance L 3 from one end then A minimum number of nodes excluding the ends are 2 B next higher number of nodes excluding the ends are 5 C frequency produced may be V 3L D frequency produced may be 3V 2L V velocity of waves in the string

n the figure shown S and S are two identical coherent sources of sound separated by d A receiver moves along line XY which is parallel to S S to detect intensity of sound at various points on the line Distance of line XY from S S is D d Distance of first intensity maxima on ine XY measured from O is y Find percentage change in value of y if the temperature of air increases by 1 If your answer is X fill value of 6X X

Note You anamping queron Answer A ball is dropped from a tower of height 30 0 m If the terminal speed of the ball is 25 0 m s then calculate the time taken by the ball to hit the ground a 2 67 s b 3 58 s c 2 47 s d 5 54 s Subject Test Submit

Two particles having position vectors 31 51 m and 2 51 31 m at t 0 are moving with velocities V 41 33 m s and V ai 73 m s For what value of a they collide at t 2 sec Block 1 sits on top of block 2 Both of them have a mass of 1 kg The coefficients of friction

3 A convex lens L and a concave lens L have refractive index Match the following two columns 2 Column l A L is immersed in a liquid of refractive 7 index B L is immersed in a liquid of refractive 8 index C L is immersed in a liquid of refractive 7 index D L is immersed in a liquid of refractive 8 index Column II p Lens will behave as convex lens q Lens will behave as concave lens r Magnitude of power of lens will increase s Magnitude of power of lens will decrease dations

If refractive index of material except vacuum for different colour will be different and variation is given as du d a where is wavelength and wavelength increases as we go along V I B G Y OR Choose the incorrect statement s A deviation will be maximum for red through any prism B white light goes from air to matter will disperse in different colours C white light goes from air to matter then violet will be closest to normal in emergent light D deviation will be maximum for violet A

37 A charge having e m equal to 108 C kg and with velocity 3 x 105 m s enters into a uniform magnetic field B 0 3 tesla at an angle 30 with direction of field The radius curvature will be a 0 01 cm b 0 5 cm c 1 cm d 2 cm

A semicircular insulated conductor of radius 0 5 m lying in x z plane is rotated at uniform angular speed of 4 rad s about an axis passing through one of the ends of the conductor say A in the presence of an external uniform magnetic field B Both the axis of rotation and the magnetic field are normal to the plane of the semicircle If the induced voltage between the ends of the conductor is 10 mV What is the strength of magnetic field in mT Z 0 D B Bo X

The mass of a density bottle is 35 g when empty 79 g when filled with water and 63 g when filled with alcohol Find the relative density of alcohol

Identify the correct statement regarding fall time of power transistor You can select multiple correct answers The time during which collector current drops from 0 1 lcs to 0 9 lcs Collector emitter voltage Starts falling up during fall time The time during which collector current drops from 0 9 Ics to 0 1 lcs Collector emitter voltage rises from 0 1 Vcc to 0 9 Vcc

A uniform rod of length L 60 cm is suspended through an end and is set into oscillation with small amplitude under gravity Find the time period of oscillation g 10 m s A B 0 4 S 0 2 TS 0 4 s 0 2 s

Two coplanar uniform identical rings of equal mass m and radius R are rigidly attached to each other at the periphery as shown One ring wears a bead of mass m The bead can slide freely without friction The other ring is hinged at point P in such a way that the structure of two rings can freely rotates about horizontal axis passing through point P The rings and beas are released from rest from position shown Then just after release O Bead The magnitude of angular acceleration of ring is 5g 17R 20 The magnitude of angular acceleration of the structure of rings is 972 20 The magnitude of acceleration of bead is 7 The magnitude of acceleration of bead is 85g g p

For the circuit shown power consumed is 3kw and the power factor is 0 75 Fir a Impedance of circuit b Resistance of coil B of coil A c Inductance R 592 00000000 A L 0 02H oooooooo B 240 V 50 Hz

d linear momentum c acceleration The three vectors whose resultant is zero mus colinear co planar b nonlinear d co axial the following examples given below which but it is not a vector quantity greate 10 m te a p