Basic Physics Questions and Answers

A 200 W and a 100 w bulbs both meant for operation at 200 V are connected in parallel When connected to G 200 V supply the power consumed by them will be Only One Correct Answer A 8 200 3 W 300 W

A convex lens of focal length 10 CM forms images having magnitude of magnification three for any two positions of object The distance between two such positions of image will be Only One Correct Answer A 9 D 50 CM 20 CM 40 CM 60 CM

A triangle ABC has its side AB 40 mm along positive x axis and side BC 30 mm along positive y axis Three forces of 40 N 50 N and 30 N act along the sides AB BC and CA respectively Determine magnitude of the resultant of such a system of forces Select one O a 90 2 N b 358 N Oc 56 4N 30 N A 0 40 mm 50 N 30 mm B 40 N

A man of mass m is standing on one end of a plank of mass 2m floating on a river The other end just touches the bank of the river as shown in figure With what minimum speed w r t the plank should the man jump to get out of the river All surfaces are smooth and plank is always in level with the bank Given that the length of the plank is 15m A 7 m s B 7 5 m s 15m Bank 9 m s D 5 m s

An ice cube of side a is kept in a gravity free hall in vacuum If the cub melts on its own find the heat released by it due to change in its shape the surface tension of the liquid is T b 6 a c 6 4 a a 6 4n Ja 2 d 6 4n Ja

1 3 are two positions a lens for which two distinct images are formed or a screen First position of the lens is at a distance of x from the object and second is at a distance 2x the focal length of the lens is 001 x 3 object 2x X 2x 2 2x 4 6x

b Draw the equivalent circuit for CE and CC modes with load resistor shorted Show that the input impedances are equal c For the circuit shown in Fig 1 i calculate IB IC and VCE if a silicon transistor is used with B 50 ii Specify a value of R so that VCE 7V BE R 100 K IB C Re 2K E Fig 1 Ic IB VCE Vcc 10 V

A cubical block of side 10cm and mass 1 kg slides down an inclined plane of inclination 37 at a constant speed of 1m s There is a thin grease layer between the block and the inclined plane of viscosity coefficient 0 3 poise then find the thickness of the grease layer um a 5 b 50 c 25 d 10

A particle is projected vertically upward with velocity v from the top of tower of height H Its velocity at a depth h below the point of projection is thrice of it velocity at a height h above the point of projection Then the velocity with which particle hit the ground is gH 2gH 4 2gH 4v 2gH

Three solid hemispheres of radii R each are placed in contact with each other with their flat faces on a rough horizontal surface A sphere of mass M and radius R is placed symmetrically on top of them The normal reaction between the top sphere and any hemisphere assuming the system to be static is A Mg 3 C Mg 3 B Mg 6 C None

Two walls of thicknesses d and d2 and thermal conductivities k and k are in contact In the steady state if the temperatures at the outer surfaces are T and T2 the temperature at the common wall is CBSE PMT 1999 MP PET 2003 AIEEE 2007 KCET 2010 k T d k T d k d k d k T k d d d k d k d T T T T kid T k d T

CHANDI UNIVERSITY Choose the correct option If in an induction motor if the supply frequency is 50 Hz and number of poles then synchronous speed will be 1500 rpm 1550 rpm 1450 rpm

Three blocks lie on each other as shown Horizontal force F variable is applied on block A Choose the correct statements g 10 m s 0 8 A 1kg F 0 2 B 2kg C2kg 11 A maximum acceleration of block B can be 2 m s B slipping between B and C cannot take place C slipping between A and B starts when F is more than 8N D maximum acceleration of block C can be 3 m s

Two tangents intersect at a chainage of 1200m the deflection angle being 38 Calculate all the data necessary for setting out a simple circular curve of radius 350m by deflection angle method The peg interval is 30m

An electrical circuit with two lamps and three ammeters with negligible resistance is set up as shown below The switch is initially open A I A 1 A A 3 A A A When the following is correct switch is closed which of the 2 A A 4 A A A

In a water fall the water falls from a height of 100 If the entire K E of water is converted into he the rise in temperature of water will be migh whs S 1 0 23 C I 2 0 46 C 3 2 3 C 0 0 033 C 10x100

1 A car covers 100 m in first 2 sec and 128 m in nex 4 sec Moving with constant acceleration The spee of car at end of 8 second is 1 5 m s C 10 m s 2 8 m s 4 12 m s

For a liquid filled in a capillary open to atmosphere if the cohesive forces are more than the adhesive forces then how many of the statement s below are correct a The liquid will wet the walls of the capillary b The liquid will not wet the walls of the capillary c Angle of contact is acute d Angle of contact is obtuse e Pressure just below the meniscus is more than the atmospheric pressure f Pressure just below the meniscus is less than the atmospheric pressure i b d e ii a c d iii b d f iv a c f

A larger heavy sphere and a small light sphere are dropped together onto a flat surface from a height h The radius of spheres is much smaller than height h the large sphere collides with the surface with velocity vo and immediately thereafter with the small sphere The spheres are dropped so that all motion is vertical before the second collision and the small sphere hits the larger sphere at an angle from its uppermost point as shown in the diagram All collisions are perfectly elastic and there is no surface friction between the spheres 12 12 13 n The angle made by velocity vector of small sphere with the vertical just after the second collision in the frame large sphere A a C 30 2 B 2a D zero Find the vertical velocity of smaller sphere just after the collision with respect to ground

C 502 D 402 12 The resistance of a tungsten wire is 1000 2 at 0 C and 1045 2 at 10 C Calculate the temperature coefficient of resistance of tungsten A 0 0045 C B 0 1045 C C 0 0010 C D 0 004 C

A parallel plate capacitor is charged to 60 C Due to a radioactive source the plate loses charge at the rate of 1 8 x 10 8 C s1 The magnitude of displacement current is 1 3 6 10 8 C S 1 2 1 8 10 8 C s 1 3 4 1 10 11 C S 1 4 5 7 10 12 C S 1

The ear ring of a lady shown in figure has a 3 cm long light suspension wire a Find the time period of small oscillations if the lady is standing on the ground b The lady now sits in a merry go round moving at 4 m s1 in a circle of radius 2 m Find the time period of small oscillations of the ear ring

10 6 meter O 10 3 meter O 10 9 meter O 10 5 meter 14 Changes in the properties as per external stimuli like temperature humidity this statement belongs to which following material Nano Material O Smart Material O Advance Material O Composite Material Request edit access

Q20 A lamp radiates power Po uniformly in all directions the amplitude of electric field strength Eo at a distance r from it is 1 Eo 2 Eo P 2 eger 3 Eo 4 Eo P 2mejer2 Pa 46cr P 8200 cr 2

In the Ingen Hauz s experiment the wax melts up to lengths 10 and 25 cm on two identical rods of different materials The ratio of thermal conductivities of the two materials is DPMT 2001 MP PET 2002 1 6 25

8 Mass M 1 unit is divided into two parts X and 1 X For a given separation the value of X for which the gravitational attraction between the two pieces becomes maximum is a 1 2 b 3 5 c 1 d 2

2 Edge Mill 2 Points The image beside shows an edge mill used for crushing or grinding in which stones roll around on their edges on a level circular bed The vertical axis rotates with an angular velocity WP The grinding stone rolls over the materials to be ground The materials are initially spread on Source wiki Jo Op m Frotal R the ground homogeneously Calculate the total force applied by the stone on the materials Hint consider rolling without sliding and precession of the stone

Test 4 Paper 18 12 2021 A block of mass 2 kg on a rough horizontal plank the coefficient of friction between the plank and block is 0 3 If the plank is pulled horizontal with a constant acceleration of 4 m s2 the distance moved by the block on the plank in 5 second starting from rest in m g 10m s A 5 B 10 C 25 D 50

One end of a metal rod of length 1 0 m and area of cross section 100cm is maintained at 100 C If the other end of the rod is maintained at 0 C the quantity of heat transmitted through the rod per minute is Coefficient of thermal conductivity of material of rod 100W m K EAMCET Engg 2000 3x10 J 6x10 J

2 2 A boat is moved uniformly along a canal by two horses pulling with forces P 890 N and Q 1068 N acting under an angle a 60 Fig A Determine the magnitude of the resultant pull on the boat and the angles B and yas shown in the figure Ans R 1698 N B 33 y 27

O 18 3 O 18 3 O 18 3 O None of Above Q20 4 Total Minimum number of angle gauges used for setting angle 49 degree 29 Minute 21 Second are O 5 O 6 9 8

two plane mirrors are arranged in a such a way that angle between them is 30 A boy pointed a light ray as shown in this figure An gle of incidence on second mirror is Need ed detail solution with diagram

The volume of an air double is doubled as it rises from the bottom of lake to its surface The atmospheric pressure is 75 cm of mercury The ratio of density of 40 The depth of the 3 mercury to that of lake water is lake in metre is 1 10 3 20 2 15 4 25

6 A Plane mirror is placed on the other side of a convex lens having a focal length of 12 cm A distinct image is formed in front of the lens towards the object when the plane mirror is at a distance of 45 cm from the lens calculate the distance of image from the lens

4 The position co ordinates of a projectile thrown from ground are given by y 12t 5t m and x 5t m The initial speed of throw is Here t is in second lete OT 1 10 m s leaihev 3 11 m s ns 2 vioo 10 4 13 m s Ls enf ex 17 m s

A thermodynamic process consists of two isobars and two isotherms The minimum and maximum temperatures are 400 K and 800 K The maximum volume is 4 times the minimum volume and cycle does positive work and the gas contained by system is an ideal diatomic gas The efficiency of the cyclic process is Options 2012 7 4 n2 2 2 12 7 2 n2 2 12 7 4 n2

5 A wire AB of length 100 cm and resistance 49 is connected in series to a battery of EMF 5 V and internal resistance 19 Potential gradient along the wire is 1 0 4 V cm 3 0 04 V cm 2 4 V cm 4 0 05 V cm

A rotor has a mass of 10 kg and is mounted midway on a 20 mm diameter horizontal shaft supported at the ends by two bearings 1 2 m apart The shaft rotates at 2000 rpm If the centre of rotor of the rotor is 0 10 mm away from the geometric centre of the rotor due to certain manufacturing defect determine a the amplitude of the steady state vibration and b the dynamic force transmitted to the bearing For shaft material E 200 GPa

1 Mac s credit card statement included 1896 00 in cash advances and 100 90 in interest charges The interest rate on the statement was 9 p a For how many days was Mac charged interest The number of days required is Round up the final answer to the nearest day as needed Round all intermediate values to six decimal places as needed

In the shown potentiometer setup length of AB is 10 m and has a resistance 20 2 If the switch in the secondary circuit is open the galvanometer gives zero deflection at 240 cm from point A If the switch is closed and R x 2 the zero deflection is at 180 cm from point A If the switch is closed and R 2 the zero deflection is at y cm from point A Then the value of y is 15V 400 www TQ www www R Options 1 90 2 120 3 60 4 80 S

A projectile is projected in the earth s gravitational with initial kinetic energy E The horizontal of the projectile range is R If the mass of the projectile is 1 kg then the angle of projection of the projectile will be equal to A sin gR 2E C 0 5sin gR 2E D 4sin gR 2E B 2sin gR 2E Three solid spheres each of mass m and radius R are released from the position shown in figure The speed of any one sphere at the time of collision would be

2 Keeping the mass of the conductor constant its radius of cross section is increased by 0 5 Calculate the percentage change in the resistance 1 Increases by 4 3 decreases by 2 2 Increases by 2 4 decreases by 1

A body is thrown vertically up with a velocity u as shown in the figure It passes through points P and Q in its upward journey and reaches the maximum height at point R Here PQ 7 PR 16 A OP C 2u 45 48 Find the velocity of the particle at point P 2 16 and take g 10 m s R of P 0 B D U 2 U 3

A sin gR 2E B 2sin gR 2E C 0 5sin gR 2E D 4sin gR 2E Three solid spheres each of mass m and radius R are released from the position shown in figure The speed of any one sphere at the time of collision would be A 2GM R B 3GM VR 4R 4R C 4R GM 3R D GM 2R

92 Two cells of emf E each and internal resistances r and r2 r r are connected in series across load resistance R If potential difference across the first cell internal resistance r is zero then th relation between R r and r is 1 R r 1 2 R 1 52 3 R r 2 r 2 4 R 1

mv The binding energy of a particle of mass m with a planet when it is on the planets surface is 2 A tunnel is dug along a diameter of the planet and the particle is dropped into it from the surface when the body reaches the centre of the planet its speed is A Vo B 2 C Zero D 2

A beam of proton particles with an energy of E 6 5 eV falls on a potential step with a height of V 2eV What is the percentage of the particles reflected 1 1 2 2 0 84 3 0 12 4 100 5 0

155 The two ends A and B of a uniform of length 1 m and mass m are moving with velocities VA and VB shown The length AP where P is point on the rod with velocity 12 m s is 8 K cm Find the value of K VA 20m s A 0A 53 BX08 37 VA

The dimensionally incorrect equation among the following is h 2 s cose s is surface tension h is height p is density r is radius g is acceleration due to gravity prg Read More V V v is velocity P is the pressure p is density 1mgl f is frequency I is moment of inertia is length m is mass 2 1 pr V is volume p is pressure difference n is coefficient of viscosity is

138 A disc of mass M radius R is placed a rough horizontal surface with its axis horizontal A light rod of 3 length 2R is fixed to the disc at point A as shown in figure and a force Mg is applied at the other end If disc starts to roll without slipping find the value of 10xmin where min is minimum coefficient of friction b w disc horizontal surface required for pure rolling R 21 R 2R Mg