Physics Questions

A particle is moving along straight line whose position x at time t is described by x t t where x is meters and t is in seconds Then the average acceleration from t 2 sec to t 4 sec is 4 10 m s 1 16 m s 2 18 m s 3 22 m s

A certain resistance was measured to be 30 2 at 20 C and 40 Q at 5 C Find the temperature coefficient at 0 C and 25 C and the ferred zero resistance temperature Ans Tx 205 C a 0 00488 C 25 0 00435 C

6 9Q An electric dipole is placed at origin with its dipole moment directed along negative x axis The direction of electric field at point 1 2 0 is 1 Along positive y axis 2 Along positive x axis 3 Along negative x axis 4 Along negative y axis

A hollow metallic cube has edge length 12 cm A liquid whose coefficient of volume expansion is 6 x 10 10 C 1 is poured into it upto height 3cm When temperature increases height of liquid in cube remains unchanged Coefficient of linear expansion of cube s material is n 10 10 C 1 find n Question Type Numerical Type

13 A silicon p n junction diode has the following parameters N 2 10 8 cm x N 2 10 6 cm T tp 2 x 10 6 s D 25 cm s and Dp 8 cm Tn Tp s A light source is incident only on the depletion region producing a generation current density of Jgen 50 mA cm 2 The diode is open circuited The generation current density forward biases the junction inducing a forward bias current in the opposite direction to the generation current A steady state condition is reached when the gen eration current density and forward bias current density are equal in magnitude What is the induced forward bias voltage at this steady state condition

Two spherical conductors of radii 4 cm and 5 cm are charged to same potential I 0 and 0 be respective charge densities of charges on both conductors then ratic of 1 is 04 5 05 4 25 16

y x515x y x as shown in the figure 20 ded by the curve and line 20 iii Find the volume solid obtained by rotating the region bounded by the curves y x 1 y 5 x realme

A wire of resistance 9 ohm is broken into two parts The ratio of cut length 1 These two pieces are connected in parallel The net resistance will be 020 030 040 50

A screening test for cancer has a low false positive rate and a low false negative rate in that with careful use one finds the disease in 95 of the patients having it and only 5 of the patients not having it Assume that 4 of a certain population has the disease What is a the probability that a person who reacts positively to the test will in fact have the disease

View In English A ball after falling from a height of 10 m strikes the roof of a lift which is descending down with a velocity of 1 m s The recoil velocity of the ball will 1 8 m s 11 m s 12 m s 15 m s 2 3 4 Correct Answer 3 Status unattempted

17 A mass of 5 kg is suspended by a string 10 m long A horizontal force is applied on the mass to pull it 5 m from a vertical line through the point of suspension Find the magnitude of the force Ans 28 29 N

Three balls are thrown from the top of a building with equal speeds at different angles When the balls strike the ground their speeds are V1 V2 and v3 respectively then 1 V V2 V3 2 V3 V2 V1 3 V V2 V3 4 V1 V2 V3

Centripetal force 1 can change speed of the body 3 is constant for uniform circular motion 2 is always perpendicular to direction of motion 4 all of these

pressibility of liquid Two soap bubbles are connected by a tube as shown in figure What happens when stopper S is removed liquid lead 1 Size of bubble A increases 2 Size of bubble B decreases 3 Both bubble take the same size 4 Size of bubble A decreases and size of bubble B increases S B

In a potentiometer arrangement a cell of emf 1 25 volt gives a balance point at cm of length of wire If cell is replaced by another cell the balance point shifts to 63 cm What is emf of second cell O 2 25 V 1 50 V O 1 75 V 2 50 V

If E represents the electric field at point A and V represents the potential at point A due to a small dipole p as shown in the diagram then which of the following relation is incorrect K E V Kp F VA E 3 p F 6 tana tane 2 kn 1 4180

A wheel of radius R rolls on the ground with a uniform velocity v The relative acceleration of topmost point of the wheel with respect to the bottommost point is 1 3 12 R 12 2 4 21 R 4v F

Like an atom when a nucleus is in excited state spontaneously decays to its ground state and a photon is emitted with energy of order of eV keV meV

Match the columns I and II Column 1 A Angle B Power C Work D Energy Length 4 MLT 2 a A 3 B 4 C 1 D 3 b A 2 B 1 C 5 D 4 c A 3 B 1 C 4 D 2 d A 2 B 1 C 3 D 4 OA OB Column II 1 ML T 3 2 MOLOTO 3 MLT 2 O C O D

Direction Analyze the problem and answer the given questions Performance task Height in meters Horizontal distance in meters A bail on the football field was kicked by Bruno The parabolic path of the ball is traced by the graph above 1 How would you describe the graph 2 What is the initial height of the ball 3 What is the maximum height reach by the ball 4 Determine the horizontal distance that corresponds to the maximum height reached by the ball 5 Approximate the height of the ball it has travelled 3 meters horizontally 6 How far does the ball travel horizontally before it hits the ground

A resistor of resistance R is connected to an ideal battery If the value of R is decreased the power dissipated in resistor will Increase Decrease O No change Battery emf is required to find power change

24 ner Two blocks of equal masses have been placed on two faces of a fixed wedge as shown in figure The lliw ditog bealm S to brege instappe niliw centre of one block is at a height h above the centre of other block The time after which the centre of two blocks will be at same level is blocks are released from position where centre of one bl 1 2h 2 2 2h m h m 60 30 3 2 3 h O 4 3h V g jong to olons uns

3 At what height from the surface of earth the gravitation potential and the value of g are 5 4 x 107 J kg and 6 0 m s 2 respectively Take the radius of earth as 6400 km a 1400 km c 2600 km b 2000 km d 1600 km NEET I 2016

Two wires of equal radii with resistivities p and p2 and length 1 and 2 respective are joined in series the equivalent resistivity of combination is P P 6 6 P P l P l P l 6 6 OP l P lz 6 6

A boy in an elevator with open roof shoots a bullet in vertically upward direction from a height of 1 5 m above the floor of the elevator The initial speed of the bullet with respect to elevator is 15 m s The bullet strikes the floor after 2 seconds Then Assuming g 10 m s 1 Lift is moving with constant speed 2 Lift is moving with upward acceleration of 5 75 m 3 Lift is moving with downward acceleration of 5 75 m

20 Three stones are projected simultaneously with same speed v from top of a tower Stone 1 is projected horizontally other two makes an angle with horizontal as shown in figure Before stone 2 hite ground the distance between 1 and 3 was found to increase at constant rate 2 5 0 3 2 Then 1 Angle 0 is 37 2 Angle 0 is 60 3 Rate at which distance between 2 3 increase is 3 v 85 8 4 Rate at which distance between 2 3 increase is V Palm 6 S V gnols privom zi eline S

Q 14 In the network shown below if 50 resistor is short circuited then value of Requals to Rea 60 ww ww 69 a 15 22 c 12 02 49 ww 40 ww 30 M eq 5002 1022 www 40 b 6 Q d 1 5 2 60

View In English If the first minima in a young s slit experiment occurs directly in front of one of the slits then the wavelength of the radiation used is assume d D 1 2 3 4 6D Correct Answer 1 Status unattempted

View In English In the circuit shown in figure K is open The charge on capacitor C in steady state is q Now key is closed and at steady state the charge on C is 92 The ratio of charges 1 is 1 Correct Answer 1 Your Answer 3 Status incorrect 3 2 2 3 www R 1 7 C 3 E K 2R 1 4 1 2

The potential at a point due to an electric dipole will be maximum and minimu when angles between axis of dipole and line joining the point to dipole are respectively 0 120 0 90 90 180 O 0 180

Nuclei of radioactive element A are produced at rate 2 where t is time at any time t The element A has decay constant A Let N be the number of nuclei of element A at any time t F time t to dN dt is minimum The number of nuclei of element A at time t to is ONO Xt 12 2to At to

Two positive charges are kept at a 0 and a 0 A negative charge then let from a position 0 y y al The negative charge will perform O Oscillatory motion only O Simple harmonic motion O Will come to rest at centre O Will move on a circular path

A wire is connected in left gap of a meter bridge balance a 100 resistor in the right gap to a point which divides the bridge wire in the ratio 3 2 The resistanc of wire is 150 18 Q 6 60 24 Q

A boy of weight 60 kg wt is standing in a lift If the lift beings to move up with a uniform speed 4 9m s the apparent weight of boy is 1 60 kg wt 2 90 kg wt 3 30 kg wt 4 zero

A mass of 5 kg is suspended by a string 10 m long A horizontal force is applied on the mass to pull it 5 m from a vertical line through the point of suspension Find the magnitude of the force Ans 28 29 N 18 One of the recton 1

1 The condition for obtaining secondary maximum in the diffraction pattern due to single slit is a is width of the slit n is order of maxima is wavelength of incident light 1 a sin 0 n2 2 a sin 0 2n 1 3 a sin 0 2n 1 4 a sin 0 n 2

A force of 5N acts on a body at rest and mass 1kg During this time the body attains a velocity of 30m s The time for which the force acts on the body is 1 10 sec 2 8 sec 3 6 sec 4 5 sec

A body of mass m placed on an inclined plane of inclination 30 with the horizontal as shown Then the acceleration of the block is g 30 m smooth fixed g 3 3g 4 g

A wheel is rotating at 720 rpm and the power supply is swtiched off the retardation is produce is 2 radian sec 2 How much time will it take to stop and how many revolution will it will make till it s stop

two concentric sphere radii r1 and r2 the charge on inner sphere and outer sphere are 2micro columb and 4 micro c olumb if two sphere are connected by wires sufficient ti me then how much charge moves from inner sphere to ou ter sphere

The Ka wavelength of an element with atomic number z is X The ka wavelength of an element with atomic number 2z is A2z How are Az and A2z related ONO Az 4A2z A 4X22 Az 4X22

S The ratio of energy required to raise a satellite to a height h above the earth surface to that required to put it into the orbit is a h 2R b 2h R hody of supercondense c R h d h R material with mass twice ll compared to the

A bar magnet of length 3 cm has points A and B along its axis at distances of 24 cm and 48 cm on the opposite sides Ratio of magnetic fields at these points will be p Apply brand Big samke N B odn 1 8 3 A 24 cm 30 11 48 cm 2 1 2 2

If the dimensions of a physical quantity are given by M Lb Ts then the physical quantity will be a velocity if a 1 b 0 c 1 b acceleration if a 1 b 1 c 2 c force if a 0 b 1 c 2 d pressure if a 1 b 1 c 2 O A O B O O O C

V 3g 8 Let E be the energy required to raise a satellite to height h above earth s surface and E be the energy required to put the same satellite into orbit at that height Then E E is equal to b a c 2h R 2h R R h 1090 2h 2R 3h 20 2R 2h R d earth with orbital which

56 The average electric field of electromagnetic waves in certain region of free space is 9 x 104 N C Then average magnetic field in same region is 1 27 x 104 T x 10 2 3 2 3 x 10 2 4 3 x 10 2

13 A block of wood floats in water with t th of its volume submerged but it just floats in another liquid The density of liquid is in kg m 1 750 3 1000 2 800 4 1250

33 What will be the work done in increasing the radius of soap bubble from solution is T 1 3nr T 3 9 r T 2 4 30m T 12 r T 2 2 to 2r if surface tension of soap

A radioactive isotopes is being produced at a constant rate X Half life of substance is Y After some time the no of radioactive nuclei become constant The value of constant is ONO XY in 2 XY In 2 XY

ROSI V00V tent de stingr AXE P etallic shell of mass M and radius R filled with water of mass M is set into pure rolling motion on a smooth ontal surface as shown in the above figure Now water is freezed suddenly and the ice sticks with the