Basic Physics Questions and Answers

Ring A can slide on a smooth horizontal rod and block B can move vertically Both are attached by an inextensible string At a certain instant velocity of ring is v and of block is v2 At that instant ring is at a horizontal distance b from pulley as shown Then wwwwwwwww VI 20 B V2 A V VICOSO B a2 a cose where a and a represent the accelerations of block and ring respectively at that instant C V V cos0 D Angular velocity of the ring with respect to an observer on the pulley is v sine a b In a photoelectric effect experiment the frequency of incident radiation is

5 The position of centre of mass of a system o particles does not depend upon which of th following characteristic A forces on particles B position of the particles C masses of particles D relative distance between the particles

A hollow glass sphere of inner radius 5 cm outer radius 10 cm is viewed as shown in figure If refractive index of glass is find distance in cm between A O as seen by the observer Assume near normal incidence of light Air B glass A Air 10cm

A 1 3 kmph B 2 4 kmph A man can row a boat with 4 kmph in still water He is crossing a river where is 2 kmph The time taken by him to row 2 km upstream is A 2 hr 1 hr C 4 hr D 3 hr lum hr The gases are ejecting from 6

Mercury level falls when a barometer is carried on a mountain It is because A the air pressure is low on the mountain B the air pressure is high on the mountain C mountain is very cold D there is less moisture in air on the mountain

17 A man standing on a road hold his umbrella at 30 with the vertical to keep the rain away He throws the umbrella and starts running at 10 km h He finds that raindrops are hitting his head vertically the speed of rain drop with respect to the road will be 1 10 km h 2 20 km h 3 30 km h 4 40 km h Two men P Q are standing at corners A B 18 3 6 km hr 17 221 422 4 Gedu 3 10 km h 18 1 10 km h 3 30 km h 2 Sm Wer baldai AR

1 19 6 N 2 25 N 3 10 6 N 4 10 N 39 The acceleration of system of two bodies over the wedge as shown in the figure is 137 1 1 ms 2 3 0 5 ms 2 2 2 ms 2 4 10 ms 39

A house hold 20 liter geyser consist of a coil of resistance R across which an ac source of rms voltage V is connected The wall thickness of geyser is t A and the inner surface area of geyser is A The average thermal conductivity of material of walls of geysers is k and S is specific heat capacity of water Assuming initial temperature of water is equal to the temperature of atmosphere The time taken to rise the temperature of water by 50 C is Neglect the specific heat of walls of geyser and radiation losses 2St 50RKA A tV V t 50RKA KA tV In B 20St In KA

sir mam I m bipc student my teacher taught me about functions recently she gave an eg y f x where y is a function x and she gave another eg y sin x where sin is a function which connects y and x MY DOUBT in the second eg shouldn t it be y is a function of sin x as y depends on sin x

The system shown in the figure is at equilibrium All the pulleys strings and spring are ideal Find the initial acceleration of block A just after the string below A is cut A 5 m s C 3 m s 0 0000 B 9kg A 3kg B 10 m s D 9 m s

Water runs into a conical tank kept with vertex downwards at the rate 9 cm sec If water level is rising at the rate of X TU cm sec when the height of water level in tank is 6 cm find x Height of cone is 10 cm and radius is 5 22 7 cm Take

If A i 2 3k and B 21 then find a vector whose magnitude is equal to component of A along B and direction is along A A C 2 21 2 2k 14 2 1 2 3k 14 B D 2k j 2 21 i 3k 14 2 i 2 3k 14

1 In a hydrogen atom an electron is revolving in a circular path of radius 5 1 x 10 11 m with frequency of 6 8 x 1015 Hz The equivalent magnetic moment is 1 8 9 x 10 24 Am 3 12 6 x 10 24 Am 32 When current chan 2 6 2 x 10 25 Am 4 5 38 x 10 25 Am

AY If stress in a stretched wire of a material whose Young s modulus is Y is 200 in order that the speed of longitudinal waves is equal to 10 times the speed of transverse waves then find value of

An electric box contains three e m f sources as shown in the figure Ao Answer A 1V 122 1V 192 2V 292 C Your Attempt OB Correct answer e m f of the electric box is V 3 B point B is at higher potential than point A C internal resistance of the box is terminal voltage for 2 V source is V

22 Two blocks of masses 3m and 2m are in contact on a smooth table A force P is first applied horizontally on blcok of mass 3m and then on mass 2m The contact forces between the two blocks in the two case are in the ratio is P3m 2mk P 2 2 3 4 5 3 22 1 1 2 3 3 2 22 a 23 2014 valst iufui a a i e 1 1 2 3 3 2 P3m

14 A bus is beginning to move with an acceleration of 1 m s A boy who is 48 m behind the bu starts running at 10 m s After what time wil the boy be able to catch the bus 1 6 s 2 8 s 3 10 s

An electric dipole consists of two equal and opposite charges of magnitude 2 C placed 25 0 03 m apart It is lying in electric field of intensity 2 x 105 N C The maximum torque acting on dipole will be 1 2 6 Nm 3 1 2 x 10 Nm 2 1 2 Nm 4 2 4 x 10 Nm

7 A string of negligible mass going over a clamped pulley of mass m supports a block of mass M as shown in the fig The force on the pulley by clamp is given by 1 2 Mg 2 2mg 3 M m g m g m M 7 tel questi

3 6 and 5 4 4 and 6 38 An object of mass 4 237 g occupies a volume 1 72 cm The density of the object to appropriate significant figures is 1 2 46 g cm 3 3 2 5 g cm 3 2 2 463 g cm 4 2 50 g cm 3

Path SKOTA RAJASTHAN 31 At a height 0 4 m from the ground the velocity of a projectile in vector form is 61 2 m s The angle of projection is g 10 m s 1 45 3 30 2 60 4 tan 3 4 31 gell 0 U 61 2 g 10 m 1 45 3 30

33 A bullet of mass m is fired at an angle of 45 with horizontal with a velocity V When it passes in the same plane at point Q its momentum will change by 1 zero P 45 mv 2 1 3 mv

4 None of these 38 A particle is projected at 60 to the horizontal 38 with a kinetic energy K The kinetic energy at the highest point is 1 K 2 zero 3 K 4 4 K 2 39 Six persons of same mass travel with same speed u along a regular hexagon of side d such that 39

A bird is flying towards north with a velocity 40 kmh and a train is moving with velocity 40 kmh towards east What is the velocity of the bird noted by a man in the train 1 40 2 kmh N E 2 40 2 kmh S E 3 40 2 kmh N W 4 40 2 kmh S W A train of 150 m length is going toward north 3 17 18 suell G 40 kmh Qala 1 40 2 3 40 2 s 150 m

Q No 6 To check the diameter of a twist drill with a micrometer the measurement must be taken across the A Margins of the drill B Flutes of the drill C Cutting edges of the drill D Lips of the drill

3 A pendulum bob of mass 8 mg carries an electric 23 charge of 39 2 x 10 10 C in a horizontal electric field of 20 x 103 NC 1 and is at rest The angle made by pendulum with vertical is nearly 1 37 2 45 3 60 4 30

Q No 8 Pick up the wrong statement Surface plates are usually made of granite because of following advantages A Because of long period of time for relaxing it is free from built in residual stresses There is no corrosion effect also B It enables the phenomenon of wringing flat surfaces over it C If a tool or work piece drops accidently over its surface residual stresses are not induced D It simply powders somewhat at the point of impact by falling object

24 A straight segment of wire is moving with velocity 7 2 k and magnetic field in the region is 41 2 Find emf induced in rod at an instant when points are located between 1 1 1 and 3 3 3 5 A thin circular ring of area A is held perpendicular to a uniform magnetic field A small cut is made in the

Q No 9 Pick up the wrong statement A Error is the disagreement between the result of measurement and actual value B Random error are regularly repetitive in nature and result from improper conditions or procedures that are consistant in action C Parasitic error results from incorrect execution of measurement D Uncertainty of measurement represents the dispersion of the result of measurement defmed by the limits of the error

In the figure a slab of refractive index 3 2 is moved towards an object which is also moving with veloicty 10 m s as shown in the figure The velocity of image seen by the observer will be 2m s 10m s 1 12 m s 2 8 m s Question Type Single Correct Type 3 10 m s H 3 2 4 18 m s air observer

Q No 3 Pick up the wrong statement A Accuracy of an instrument is closeness to the true dimension B Precision represents the degree of repetitiveness C Sensitivity refers to minimum change in value that the instrument can reliably indicate D As the sensitivity of an instrument increase its range of measurement also increases

If in a new system unit of length is 2m unit of time is 3s then x is the numerical value by which gravitational acceleration g 10 m s is represented in new system of unit Fill the value of in OMR All the strings springs and pulleys shown in figure are ideal Initially the system is in equilibrium and

The period of oscillation of a simple pendulum is T 2 L g Measured value of L is 10 cm known to 1 mm accuracy and time for 100 oscillations of the pendulum is found to be 50 s using a wrist watch of 1 s resolution What is the accuracy in the determination of g a 2 b 3 c 4 d 5

13 A particle is moving along x axis It starts from 10m 0 and goes to 30 m 0 Now it returns along the same line and reaches at point 20m 0 What is value of its displacement and distance travelled 1 20m 80m 2 20m 70m 4 30m 80m 3 30m 70m

transmission cables from powe station carr y current at very high voltage reason power dissipation in cables is directly propo rtional to the square of the voltage assertion equipotential surface is normal to electric fe ild lines reason potential increases in the direction of the el

1 velocity 3 2 3 distace 2 2 distance 4 velocity 2 3 43 Consider the velocity time graph given below It represents the motion of 2 8 10 12 14 1 a projectile projected vertically upward from a point 2 a car with constant acceleration along a straight road 3 a bullet fired horizontally from the top of a tower 4 an object in the positive direction with decreasing speed

4 If the moment of inertia of a disc about an axis which is along its diameter is I then the momen of inertia about the axis passing through its centr and perpendicular to plane is NCERT Pg 165 2 1 2 4 114 1 3 2

A body of mass m 1 8 kg is placed on an inclined plane the angle of inclination is a 37 and is attached to the top end of the plane with a thread which is parallel to the slope Then the plane is moved with a horizontal acceleration of a Friction is negligible 3 mg Find the acceleration if the body pushes the slope with a force of 4 A 5 m s B 0 5 m s C 0 75 m s D 2 m s

Q No 23 In a sine bar the standard length is measured from A Edge to edge B Between inner circumference of two rollers C Between outer circumference of two rollers D Between the centres of two rollers Knowledge Sections

Q No 17 Pick out the wrong statement about Taylor s principle of gauging A Go gauges should be full form gauges B Go gauges should check all the related dimensions simultaneously C It is sufficient to use Go gauges on the width and length of the component D Not Go gauges should check only one dimension at a time

A small metallic ball moves through a fluid with a speed v in downward direction experiences a force F which acts in upwards direction Experimentally the magnitude of this force depends on radius r of ball velocity v of ball and viscosity h of fluid The correct relation between F r v and h is given by XFx nn 2 F n rv 3 F nr v t

Power transfer by a non ideal cell to an external resistor can be same for two different values Out of which one value R is less than internal resistance of cell and another R is greater than internal resistance of cell then Question Type Single Correct Type 1 R will give less internal loss 2 R will give more battery life 3 R will give less efficiency will my life

3 A uniform metre scale weighing 100 gf is pivot at a point O a 25 cm mark A 80 gf weight is hung from 10 cm mark and a 30 gf weight is hung from 70 cm mark as shown in the figure Calculate a the total anticlockwise moment about point O b the total clockwise moment about point O and c the net resultant moment 0 10 25 80 af Ko 50 70 100 gf 30 gf 100

A current of 4 ampere is passing through a conductor which is having a potential difference of 10 V Its conductance is 1 0 4 s 2 2 5 s 3 40 s 4 4 sl bulb works on 230 V line

The diagram shows 2 different boxes A and B 8 different toys are to be placed in the boxes Find the number of ways in which the 8 toys can be placed in the boxes so that 5 toys are in box A and 3 toys are in box A B

18 4 32 3 3 30 km h Q Two men P Q are standing at corners A B 18 8m ugd ABCD of square ABCD of side 8m They start moving along the track with constant speed 2m s and 10 m s respectively The time when they will meet for the first time is equal to 10 m s 1 2 sec 2 m s PL 2 3 sec 3 1 sec 4 6 sec 10 m swell 1 2 sec sollt 2 m s PL 2 3 sec

3 310 cm 4 337 cm An insect starts climbing a conical birthday hat of radius 7 cm at base It starts from point A and reaches point B taking spiral path on the hat Find out its displacement if height is 24 cm 24cm 1 12 cm 3 13 cm cm 2 8 cm 4 25 cm 45 7 E

The displacement time graph for two part A and B are straight lines inclined at an of 30 and 60 with the time axis The of velocity of particle A B V V 1 1 2 B 130 2 1 5

A ship A is moving westwards with a spe 10 km h and a ship B 100 km south of moving northwards with a speed of 10 B The time after which the distance between becomes shortest is 1 5 h 3 10 2h 2 5 2h 4 0 h

Two points P and Q are maintained at potential of 8 V and 7 V respectively The work done in moving 105 electrons from P to Q is 2 4 x 10 13 J 1 6 10 13 J 1 6 10 13 J 2 4 10 13 J