Physics Questions

149 For a parallel beam of monochromatic light of wavelength A diffraction is produced by a single slit whose width a is of the wavelength of the light If D is the distance of the screen from the slit the width of the central maxima will be 2015 a c D a 2Da b d Da a 2D a

In Young s experiment two coherent sources are placed 0 90 mm apart and fringe are observed one metre away If it produces second dark fringe at a distance of 1 mm from central fringe the wavelength of monochromatic light used would be 1991 1992 a 60 104cm c 10 x 10 5 cm b 10 x 10 cm d 6 x 10 5 cm

View in English Three resistance P Q Reach of 30 and an unknown resistance Sform the four arms of a wheatstone bridge circuit When a resistance of 6 Q is connected in parallel to S the bridge get balanced What is value of S 0 60 0 40 9 30

ERT T P is not Which of the following phenomenon common to sound and light waves 1988 a Interference c Coherence b Diffraction d Polarisation 19891

53 The intensity at the maximum in a Young s double slit experiment is Io Distance between two slits is d 52 where is the wavelength of light used in the experiment What will be the intensity in front of one of the slits on the screen placed at a distance D 10 d 2016 a In 3 b d Io 4 2

146 A beam of light of 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away The distance between first dark fringes on either side of the central bright fringe is 2014 1 a 1 2 cm c 2 4 cm In the Young s double slit experiment the 5 b 1 2mm d 2 4mm

150 At the first minimum adjacent to the central maximum of a single slit diffraction pattern the phase difference between the Huygen s wavelet from the edge of the slit and the wavelet from the midpoint of the slit is 2015 RS

A uniform rope of length L lies on a table If the coefficient of friction is p the maximum fractional length of the hanging part of the rope from the edge of the table without sliding down will be O 1 Read More 4 1

6 There are four concentric shells A B C and D of radii a 2a 3a and 4a respectively Shells Band D are given charges q and q respectively Shell C is now earthed The potential difference V Vc is k 1 k c kq 2a kq b G kq 3a kq 6a fal ding Band

screen in case of D In Young s double slit experiment the distance between the slits and the screen is doubled The separation between the slits is reduced to half As a result the fringe width NEET Kar 2013 a is doubled b is halved c becomes four times

18 Four point charges A B C and D are placed at the four corners of a square of side a The energy required to take the charges C and D to infinity they are also infinitely separated from each other is q B q 20 10 ATEA b 2q c ATS a 2 1 d 9 65 1

An inductor 20 10 3 henry a capacitor 100 F and a resistor 500 are connected in series across a source of EMF V 10 sin 314t If resistance is removed from the circuit and the value of induc tance is doubled then the variation of current with time in the new circuit is 2014 a 0 52 cos 314 t c b 0 52 sin 314t 052 sin 314t 7 3 d None of these

Q 16 A current of 2 5 0 05 A flows through a wire and develops a potential difference of 10 0 1 volt Resistance of the wire in ohm is A 4 0 12 B 4 0 04 O O O O A B O C D C 4 0 08 D 4 0 02

P A parallel beam of fast moving electrons is incident normally on a narrow slit A fluorescent screen is placed at a large distance from the slit If the speed of the electrons is increased which of the following statements is correct ore NEET 2013 a The angular width of the central maximum of the diffraction pattern will increase b The angular width of the central maximum will decrease The angular width of the central maximum will be unaffected bo d Diffraction pattern is not observed on the c

9 A billiards player hits a stationary ball by an identical ball to pocket the target ball in a comer pocket that is at an angle of 40 with respect to the direction of motion of first ball Assuming the collision as elastic and friction and rotational motion are not important the angle made by the target ball with respect to the incoming ball is 1 40 2 50 3 45 4 60

A hollow conducting sphere is placed in an electric field produced by a point charge placed at point A as shown in the figure Let VB and Vc be the electrostatic potential at points B and C respectively then A B VB Vc VB Vc VB Vc C

View in English A potentiometer consists of a wire of length 8 m and resistance 20 Q It is connected to a cell of e m f 4 V The potential difference per unit length of the wire will O 4 V m O 1 V m O 0 5 V m O 5 V m

29 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 1 2 4 x 10 13 J 3 1 6 x 10 13 J 2 1 6 10 13 J 4 2 4 10 13 J

If yellow light emitted by sodium lamp in Young s double slit experiment is replaced by a monochromatic blue light of the same intensity a fringe width will decrease b finge width will increase 1992 c fringe width will remain unchanged d fringes will become less intense

Q 2 Two batteries one of the emf 3V internal resistance 1 ohm and the other of emf 15 V internal resistance 2 ohm are connected in series with a resistance R as shown If the potential difference between a and b is zero the resistance of R in ohm is A 5 B 7 C 3 D 1 O A O B O c C C 3V 10 15V 202 R

In Young s double slit experiment the fringe width is found to be 0 4 mm If the whole apparatus is immersed in water of refrative index 4 39 without disturbing the geometrical arrangement the new fringe width will be 1990 a 0 30mm b 0 40mm c 0 53 mm d 450 microns

7 A lens having focal length fand aperture of diameter d forms an image of intensity I Aperture d of diameter in central region of 2 lens is covered by a black paper Focal length of lens and intensity of image now will be respectively 2010

A A dielectric slab of thickness d 2 and dielectric constant 2 is inserted in capacitor as shown in figure If capacitor is connected to 10 V emf battery then find potential difference between the two surface A and B of dielectric slab Question Type Single Correct Type 1 B 4 V 20

An electron is moving in a circular orbit of radius r makes N rotations per second The magnetic field produced at the centre has a magnitude O HoNe 2r O N e 2r HoNe

The electric field in a region of space is E 1 4 3k kN C The electric flux due to this field over an area i 1 m is 1 2 x 103 N m C 1 3 3 103 N m C 1 the 2 4 103 N m C 1 4 3 10 N m C 1 arrangement of the charges

A stone of mass m falls from the top of a tower of height 150 m The stone s position y measured down from the top of the tower where y 0 as a function of time t is given as mg y t k m g k 1 e kt m where g is the gravitational acceleration and k is the air resistance coefficient Assuming that m 0 5 kg g 9 81 m s and k 0 01 kg m find numerically the time required for the stone to hit the ground Achieve an accuracy of six decimal places

Q 11 In the circuit shown the resistances are given in ohms and the battery is assumed ideal with emf equal to 3 0 volts The resistor that dissipates the most power is A R B R C R D R O A O B O C 3V 50 2 ww R R 600 R 50 02 R 30

An object is kept on a smooth inclined plane of inclination 0 The horizontal acceleration to be imparted to the inclined plane so that the object is stationary relative to the incline is A gsine C gtane B gcose D gcote

Q 17 If X Y and Z in figure are identical lamps which of the following changes to the brightnesses of the lamps occur when switch S is closed O O O A X stays the same Y decreases C X increases Y stays the same O A OB O C B X increases Y decreases D X decreases Y increases

of A is twice that of B Under such conditions the density of A is found to be 1 5 times th Two vessels separately contain two ideal gases A and B at the same temperature The pressur density of B The ratio of molecular weights of A and B is A 2 C 1 1 2 B 3 4 D CCR

Two cells of emf E and E2 are joined in series and the balancing length of potentiometer wire 550 cm If the terminal of E is reversed the balance length obtained is 150 E cm Given E E the ratio will be O 2 3 O 317

There are two metallic spheres of same radii but one is solid and other is hollow Then 1 Solid sphere can be given more charge 2 Hollow sphere can be given more charge 3 Both can be given equal amount of maximum charge 4 Any amount of charge can be given to both

7 The electric potential in a region is represented as V 2x 3y z Obtain expression for electric field strength A 21 3j k C 2i 3 k B 21 3j k D 21 3j k

Ratio of intensities of two waves are given by 4 1 Then the ratio of the amplitudes of the two waves is 1991 a 2 1 c 4 1 124 b 1 2 d 1 4 ment carried out with

Explain the difference between work in Physics and work as done every day example If you push a cart inside a store are you doing any work Describe an real world application of impulse momentum theorem J F dt mv mv0

Two capacitors of capacitances C and 2C connected in parallel and are charged to a potentia difference of V If now battery is removed and a material of dielectric constant k is placed between plates of capacitance C the potential drop across this capacitor will be 1 3 V 2 K 3 3K V 2 2 4 3V K 2 2V K 3

109 Statement A A tree showing seasonal activity shows typical S shaped curve Statement B in determining Gravity does not play any kind of role plant growth Read above statements and choose the correct option 1 Only statement A is correct 2 Only statement B is correct 3 Both statements are correct

Q 13 A storage battery is connected to a charger for charging with a voltage of 12 5Volts The internal resistance of the storage battery is 192 When the charging current is 0 5 A the emf of the storage battery is A 13 Volts B 12 5 Volts C 12 Volts D 11 5 Volts O O O O A B O C

20 Five cells each of internal resistance 0 22 and e m f 2 V are connected in series with a resistance 402 The current through the external resistance is a 0 2 A b 00 5 A c 1 A d 2 A O O O a O b C d

27 A solid conducting sphere of radius 10 cm is enclosed by a thin metallic shell of radius 20 cm A charge Q 20 C is given to the inner sphere now inner sphere is connected to the shell by a conducting wire the amount of heat generated in process is 1 6 J 3 12 J 2 9 J 4 14 J

Choose the correct alternative A x x is a positive integer and x 64 0 B y y is a natural number which divides 42 C z z is a two digit natural number such that the sum of its digits is 7 D w w is the sum of any three factors of 12 Find n A n B n C n D O 8 9 O 173 12 O 4 3 O None of these

A Equal wavelengths have equal linear momenta B Equal energies have equal linear momenta C Equal linear momenta have equal wavelengths D Equal frequencies have equal linea momenta

The fundamental frequency of a string stretched with a weight of 4 kg wt is 25 Hz The weight required to produce its octave is Neglect change in linear mas density O 4 kg wt O 12 kg wt Read More O 16 kg wt

O A body cools from a temperature 3T to 2T in 10 minutes The room temperature s T Assume that average method of Newton s law of cooling is applicable The emperature of the body at the end of next 10 minutes will be O O 7T 4 3T Read More 4T 3 questions Out of these 15 questions

139 If the pressure of hydrogen gas is increased 14 from 1atm to 100 atm keeping the hydrogen ion concentration constant at 1M the voltage of the hydrogen half cell is at 25 C will be A 0 059 V C 0 295 V B 0 059 V D 0 118V

119 The activity of a radioactive sample is measured as 1850 counts per minute at t 0 and as 185 counts per minute at t 10 minute The decay constant is approximately A 0 230 per minute B 0 461 per minute C 0 691 per minute D 0 922 per minute

9 An object is attached to a horizontal spring and somewhere along its motion has a kinetic and potential energies of 19 4 Joules and 24 9 Joules respectively Given the maximum displacement of the spring of 2 72 m the spring constant N m is

Resistance of 6 Q each are connected as shown in diagram when the current 1 A is flowing as shown The potential difference Vp Vois 6 52 692 692 www 602 www 692 O 3 V O 6V 09V Read More 602 www

A satellite is moving with a constant speed v in circular orbit around the earth An object of mass m is ejected from the satellite such that it just escapes from the gravitational pull of the earth At the time of ejection the kinetic energy of the object is 3 mv 2 72 2 my

The apparent frequency and real frequency of sound are same A If source of sound and observer are moving in the same direction with sam speed 3 If source of sound and observer are moving in opposite direction with same speed A is true B is false O A is false B is true Read More Both A and B are true