Physics Questions

radius of circle in which the ring moves is 2 5 m The speed in m s of the ring is x Find x Take An ideal string ACB passes through a smooth ring of mass m 5 kg as shown in the figure The acceleration due to gravity 10m s 2 5 m A B 37 53 C 95 kg 6 PHYSICS

An electron charge e mass m is revolving 1 around a fixed proton in circular path of radius r The magnetic field at the centre due to electron is 1 0 Ho e 2 Ho e 8 r m or Moe Uch Scat BRT V 1 0 Rr f Hoe

is taken across load resistance 6 ks if current In the given circuit Zener diode regulated voltage through 0 5 ks resistor is 4 mA then current in load resistor is V 10 V 1 2 67 mA 2 1 33 mA 0 5 k www 2 4 mA 4 2 mA 6 k

In a cyclotron a charged particle 1 undergoes acceleration all the time 2 speeds up between the dees because of the magnetic field 3 speeds up in a dee 4 slows down within a dee and speeds up between dees 9 fan til E 1 2 3 4 HE

Q28 If a cylinder containing a gas at high pressure explodes the gas undergoes A Reversible adiabatic change and fall of temperature B C D Reversible adiabatic change and rise of temperature Irreversible adiabatic change and fall of temperature Irreversible adiabatic change and

A ferromagnetic material has a Curie temperature 100K Then a its susceptibility is doubled when it is cooled from 300K to 200K b all the atomic magnets in it get oriented in the same direction above 100K c the plot of inverse susceptibility versus temperature is linear with a slope To d the plot of its susceptibility versus temperature is linear with an intercent T

here what wil mass unit 21 When 1 kg of ice at 0 C melts to water at 0 C the resulting change in its entropy taking latent heat of ice to be 80 cal C is a 8 x 104 cal K b 80 cal K c 293 cal K d 273 cal K

Question No 1 A double slit interference experiment is carried out in air and the entire arrangement is dipped in water as a result the ratio of path differences for fifth minima is A B 413 X 1

Q 16 Why the diver stretches her arm and leg while touching the water a to increase her moment of inertia b d c to relax her body to decrease her moment of inerti to increase her velocity

Eight connected in the circuit as shown in figure The equivalent resistance between A and B is C A B C A 013 16 2 3 15 7 19 2 wwww www B E www D Correct Answer

In the arrangement shown in figure the strings are light and inextensible The surface over which blocks placed is smooth Find a the acceleration of each block 14kg 2kg kg F 14N b the tension in each string

Each atom of an iron bar 5cmx1cmx1cm has a magnetic moment 1 8x10 2A m What will be the magnetic moment of bar in the state of magnetic saturation in A m Density of iron 7 78 10 kg m Atomic weight of iron A 58 Avogadro number M 602 10 3 mol

A uniform rod of mass m and length I is suspended through a light wire of length and torsional constant k as shown in figure The time periods of the system for small oscillations in the vertical plane about point of suspension is find the value of

In an interference of light derived from two sl apertures if at some point on the screen yellow light has a path difference of 32 2 then the fringe at that point will be 1 yellow in colour 3 dark 2 white in colour 4 bright WOOO

2 The transition from the state n 3 to n 1 in a hydrogen like atom results in ultraviolet radiation Infrared radiation will be obtained in the transition from a 21 c 4 2 b 32 d 43 Mains 2012

Magnetic field at the centre of a circular loop area A is B The magnetic moment of the l is 1 3 BA Ho BAVA I TT 2 4 BAVA Ho 2BA A

In a series LCR circuit when an alternating voltage of peak value 500 V angular frequency 100 rad s is applied the peak voltage drops across L C and R can be respectively 0 200 V 300 V 0 800 V 500 V 400 V 600 V 200 V 300 V 1200 V 1600 V 300 V

The order of magnetic field for human nerve fibre is 1 10 2 2 10 0 3 10 12 4 10 5 16 day 11 1 10 2 2 10 10

4 A resistor of 40 ohms is in series with two resistors A and B in parallel The resistance of A is 100 ohms The entire series parallel circuit is connected acros 120 volt supply Determine the resistance in ohms to which resistor B must be adjusted in order that current to entire circuit to be 1 2 amperes Solution 200 Q 175 Q 125 Q O 150 Q

1 New Zealand is situated in southern hemisphere 44 and Russia is situated in Northern hemisphere The angle of dip at New Zealand and Russia are 8 and 8 respectively then 1 8 up 8 up 2 8 down 8 up 3 8 up 8 down 4 8 down 8 down fera SH 1 8 2 8 3 8 4 8

c 99 m s d 86 m s The second s hand of a watch has length 6 cm Speed of end point and magnitude of difference of velocities at two perpendicular positions will be RPET 1997 b 8 88 and 4 44 mm s d 6 28 and 8 88 mm s a 6 28 and 0 mm s c 8 88 and 6 28 mm s A sphere of mass m is tied to end of a string of length I and rotated through the other end along a horizontal circular path with speed v The work done in full horizontal circle is 67 68 An unbanked curve which a 0 75 a c A wheel then the diameter of a 1 5 m HINT

Can you explain to me as to what is meant by the line tha the component of velocity along the direction of force i s changed This implies that if a force is applied at some angle to the velocity of the body then only the component of velocity along the direction of force is changed The component of velocity normal to the force remains unchanged iii The equation F ma is applicable to a single point portiola Onl

Consider the motion of the tip of the minute hand of a clock In one hour B A The displacement is non zero C The average speed is zero D The distance covered is zero The average velocity is zero Which of the following statement is not true A If displacement covered of a particle is zero then distance covered may or may not be z If the distance covered is zero then the displacement must be zero B C D The numerical value of ratio of displacement to distance is equal to or less than one The numerical value of the ratio of velocity to speed is always less than one

A particle start from rest and then moves with uniform acceleration It covers x m in 1st second What is the distance travelled by it in x seconds from start 1 x m 3 x 1 m 2 1 m 4 3x m 10

During an isothermal expansion a confined ideal gas does 150 J of work against its surroundings This implies that a 300 J of heat has been added to the gas b no heat is transferred because the process is isothermal c 150 J of heat has been added to the gas d 150 J of heat has been removed from the gas

Oscillating metallic magnetic field directed perpendicular to the plane of oscillation a slows down b becomes faster c remains unaffected oscillates with changing frequency

Two resistances R and R are made of different materials The temperature coefficient of the material of R is a and that of the material of R is B The resistance of the series combination of R and R does not change with temperature then the ratio of resistances of the two wires at 0 C will be 1 3 a B 2 B R 2 a 4 2215 10 1

25 R is connected to a wire bent in the form of a sine curve to form a closed loop as shown in the figure If the loop carries a current and is placed in a uniform magnetic field B then the total force acting on the sine curve is 1 2BIR downward 3 BIR upward XX S XX R X 2 2BIR upward 4 Zero

r r A stone of mass of 16 kg is attached to a string 144 m long and is whirled in a horizontal circle The maximum tension the string can withstand is 16 Newton The maximum velocity of revolution that can be given to the stone without breaking it will be a 20 ms b 16 ms 1 c 14 ms 1 d 12 ms 1 65 66 c 10 47 degis A body of mass 18 constant velocity a 10 SCRA 1994 c 100 r J A particle comes bu it is 10 con The

33 A body projected vertically from the earth reaches a height equal to earth s radius before returning to the earth The power exerted by the gravitational force is greatest a at the instant just before the body hits the earth b it remains constant all through c at the instant just after the body is projected d at the highest position of the body through diagram 1

A glass tube 80cm long and open at both ends is half immersed in mercury Then the top of the tube is close and it is taken out of the mercury A column of mercury 20cm long then remains in the tube The atmospher pressure in cm of Hg is 1 50 2 60 3 70 4 80

s A body projected vertically from the earth reaches a height equal to earth s radius before returning to the earth The power exerted by the gravitational force is greatest a at the instant just before the body hits the earth b it remains constant all through c at the instant just after the body is projected d at the highest position of the body

EXERCISE 13 2 Half life of a radioactive element is 40 minute What amount will remain undecayed after 4 hour 1 1 32 3 1 128 1 2 64 4 1 16 lives and to respectively W

the switch is made closed the current induced in the circuit is X X 1 X 2 X X A D Bolv R X 3Bolv R 2Bolv X X X R wwww X X X X X X X B C X X Bo X X X X

A long solenoid has 50 turns per meter of its length If current of 5 A is passed through it then the magnetic field at the end of the solenoid will be nearly equal to 0 77 Mark O 0 16 mT O 1 2 mT 1 67 mT

10 An arbitrary vector can be expressed as a sum of three mutually perpendicular unit vectors each multiplied by scalar constant equal to 1 a same scalar constant b d some scalar constant scalar constant equal to 1

A man starts from point P and goes 20 m due East then 5 m due North then 35 m due West and finally 25 m due South His displacement from point P is 1 25 m at tan 1 West of South 2 85 m in South West 3 25 m at tan 4 15 m at tan 1 West of South 3 West of South

Q 3 a c A frizzy drink beverage bottle is kept on a balance and the cap is opened Will there be any change in the balance There will be no change weight will decrease b d weight will increase weight will initially crease then decrease

3 SK 4 6k 44 In the arrangement shown all surfaces are frictionless The rod R is constrained to move vertically The vertica acceleration of R is a and the horizontal acceleration of the wedge W is a The ratio is equal to 1 sina 3 tana W 2 cosa 8

A rectangular plate of mass M of dimensions a x b is hinged along one edge The plate is maintained in horizontal position by colliding a ball of mass m per unit area elastically 100 times per second this ball is striking on the right half shaded region of the plate as shown in figure Find the required speed of the ball ball is colliding in only half part of the plate as shown It is given M 3 kg m b 2 m a 1 m g 10 m s 0 01 kg JEE 2006 6 184 b 2 XX a

4 All of the above If a magnet of pole strength m is cut into four 2 parts such that length and width of each part is half that of initial one then pole strength of each part 1 m 4 2 m 3 m 8 4 m 2 3 NA GIRAN 31 12 1 m 4

cup of coffee has a temperature of 80 C when it is poured and allowed to cool in a room with a temperature of 30 C After 1 minute the temperature of the coffee 5 C Determine the temperature of the coffee at time t How long must you wait until the coffee is 35 C 0 Jse integers or decimals for any numbers in the expression Round to four decimal places as needed

straight lin 4 parabolic A long hollow tube is carrying an electric 3 urrent along its length distributed uniformly n its circumference The magnetic field 1 increases linearly from the axis of the surface 2 is constant inside the tube 3 is zero only on the axis is zero just out side the tube 3 FREIT uch akit ataci granta 1 2 3 3 4 3

and variable temperature For an ideal gas the fractional change in its volume per degree rise in temperature at constant pressure is equal to T is absolute temperature of gas 1 7 3 7 1 2 T 4 72

4 magnetic equator The magnetic field is now thought to arise due 41 to electrical currents produced by convective motion of metallic fluid consisting mostly of molten iron and nickel in the outer core of the earth This is known as the 1 dynamo effect 2 tidal effect 3 both 1 and 2 4 None of these 3 et 34 1 2 3 1 2 4

20 A body of mass m is attached to the lower end of a spring an whose upper end is fixed The spring has negligible mass supe When the mass m is slightly pulled down and released it oscillates with a time period of 3 s When the mass m is increased by 1 kg the time period of oscillations becomes 5 s The value of m in kg is 3 a 4 b 4 3 c 16 9 9 Lun 22 16

A long straight hollow conducting tube carrying a current along ve y axis as shown in the figure The line PQ is parallel to positive y axis The magnetic field at 1 2 3 and 4 is B B2 B3 and B4 respectively Then R R 2 R 4 42 3

n tell on what thing it depends on And explain following q uestion s solution Thank you Have a great day ahead At 20 m from a line source the loudness of the sound is 40 dB At 10 m from the source the loudness will be 43 dB 46 dB 80 dB 37 dB

18 In a Young s double slit experiment the intensity at the central maximum is The intensity at a distance 3 4 from the central maximum is is fringe width 1 3 2 4 lo 2 lo

A uniform copper rod of length 50 cm and diameter 3 0 mm is kept on a frictionless horizontal surface at 20 C The coefficient of linear expansion of copper is 2 0 x 10 5 K and Young s modulus is 1 2 x 10 1 N m The copper rod is heated to 100 C then the tension developed in the copper rod is 2 36 10 N 4 Zem 1 12 x 10 N 3 18 x 10 N