Basic Physics Questions and Answers

In displacement method experiment the image of an object on the screen is formed by a convex lens of focal length 5 cm at two different location separated by 24 cm The distance between object and screen is OA 30 cm DB 40 cm Oc 60 cm D 36 cm

If Hi represents the refractive index when a light ray goes from medium i to medium j then the product 12 23 344 is equal to O 2H4 1 3 0 1 4 41 O 2H 3 Marks 4 1

A uniform chain is placed at rest on a rough surface of base length and height h on an irregular surface as shown Then the minimum coefficient of friction between the chain and the surface must be equal to n Find n h O 0 25 O 0 5 4

Two disks of masses m and m are connected by a spring of force constant k The lower disk of mass m lies on a table and the upper disk is vertically above it Figure What vertical force F should be applied to the upper disk so that when the force is withdraw the lower disk is lifted off the table m 000000 m

A series LCR circuit is in resonance at a frequency At the best phasor diagram 2 representing the relation between current and voltage phasor is 1 3 V 2 4 V V

2 A capacitor is connected across a battery for charging Current through the battery at an instant is 3 A Displacement current through the capacitor at that instant is 1 3 A 3 2 A wave transporte 2 1 5 A 4 2 5 A aneroi If at any

In a Young s double slit experiment the two slits are illuminated by a monochromatic light source S of wavelength 400 nm SS 10 m and SS is 50 m If the number of maxima formed on screen is n find n 10 S S S d 10 m D 1m O

Which of the circuit is represented by the given phasor diagram E bot Purely inductive circuit Purely resistive circuit O Series R C circuit Purely capacitive circuit t

7 Calculate the number of atoms per unit cell for rock salt crystal Given a 5 63 Mol wt of NaCl 58 5 and the density is 2180 kg m Ans 4 Atoms

the work done per is defined as voltage charge Statement 2 work done by an electric force on unit positive charge to move it through a distance I from A to B is called voltage Which of following statements are correct a nd why the statement is correct

Q 2 A rocket rises vertically up from the surface of earth so that its distance from the earth s surface is d ct2 where c is a constant After 10 s the rocket has travelled 2 km Determine its speed in m s at that moment 1 100 4 400 2 200 3 300

32 Select from the following that is true Given q ML 1T 1 Here v A and t represent velocity area and time respectively dv 3 q 1 q A 3 5 3 5 1 dv A dt 2 q A dt dv 4 None of these

21 A conduting rod of length I is moving with velocity v in perpendicular magnetic field B Resistance of rod is R then current in rod is 1 Blv R 2 Blv1 3 zero B v 1

The displacement covered by particle with time is given by x 2t 3t what will be instantaneous velocity of particle at t 2sec chad a far x 2t 3t for an 1 12 m s 2 14 m s cial 3 16 m s t 2sec 3 4 8 m s

8 The displacement wave graph for two sound waves P and Q are shown in figure Then the Ip ratio of their intensities is equal to la Assume speed of wave and density of medium is same for both waves Y Q AS 4 2 2 4 1 1 4 2 4 1 3 1 1 X

A fish is rising up vertically inside a pond with velocity 4 cm s and notices a bird which is diving vertically downward and its velocity appears to be 16 cm s to the fish if refractive index of water is 4 3 then velocity in cm s of fish with respect to bird is

Q63 Object is placed in front of a concave mirror of focal length 30 cm Magnification is found to be 3 what will be the location of Image of the object Ops A O 30 cm right to the mirror B 40 cm left to the mirror C O 20 cm right to the mirror D O 60 cm left to the mirror 56534

Given these loads q1 18 Cenx 1 0cm q2 30 Cenx 2 0cm and q3 12 Cenx 5 0cm find the magnitude and direction of the net force exerted on the charge q 2 due to the other two To indicate the direction only To the right of q2 or To the left of q2 will be accepted

4 Two particles A and B both of mass m are connected by a light string and are initially at rest on a smooth horizontal table with the string just taut Particle A is projected with a horizontal velocity at right angles to AB Find the velocities of A and B when the string has turned through a right angle B

magnetic field region with velocity v perpendicular to magnetic field B The change in kinetic energy of particle after it travels a distance d is Ignore gravity AKE 2qvBd O AKE 2qvBd AKE Zero AKE qvBd

In a closed circuit the electric current at any instant of time t in s is given by an equation 4 0 08t How many electrons flow through circuit in current flow duration 6 25 1020 O 4 x 1025 4 5 x 10 22 3 x 1025

Q 14 Consider a grounded conductor with a spherical cavity in it A point charge Q is placed in it The electric potential at the center of the cavity is volts Given K 9 x 109 Nm C a 1 m b 12 m Q 1 x 10 1 3 a 2 7 3 2 4 9

A copper wire of length 25 cm is in a magnetic field of 0 20 T If it has a mass of 10 g what is the minimum current through the wire that would cause a magnetic force equal to its weight a 1 3 A b 1 5 A C 2 0 A d 4 9 A

If a proton deutron and a particle on being accelerated by the same potential difference enters perpendicular to the magnetic field then the ratio of their kinetic energies is 4 fayakk card un gran ca ch 1 1 2 2 2 2 2 1 3 12 1 4 1 1 2

order of actions will be point B between extreme positions A and C Net force acting on the bob at these three points is correctly shown by B A A A A B 1 2 3

In relation to time varying magnetic flux induced electric field is Non conservative Conservative Having field lines as closed loops Roth 1 on

The potenital energy U in joule of a particle of mass 2 kg moving in X Y plane follows the law U 2x 4y where x y are the co ordinates in meter of the particle If the particle is at rest at 4 4 at time t 0 then Choose the incorrect statement Select an answer A B D at t 2 2sec the particle crosses the y axis at t 2sec the particle crosses the X axis The particle has kinetic energy of 40 joule when it crosses y axis The kinetic energy of the particle when it crosses X axis is 40 joule

In YDSE both the slits produce equal intensities on the screen A 100 transparent slab is placed in front of one of the slits Now the intensity at the geometrical centre of the screen becomes 75 of the previous intensity The wavelength of the light is 6000 and Hglass The thickness of the slab is 3 2 O 0 2 um O 0 3 km 0 0 4 km 0 5 m

A 10 F capacitor is charged to a potential difference of 1000 V The terminals of the charged capacitor are disconnected from the power supply and connected to the terminals of an uncharted 6 F capacitor What is the final potential difference across each capacitor 1 167V 2 100V 3 625V 4 250V dio 100V and total onoray is transferr 000

4 74 A ball with a speed of 9 m s strikes another identical ball such that after collision the direction of each ball makes an angle 30 with the original line of motion Find the speeds of the two balls after the collision Is the kinetic energy conserved in this collision process G

5 60 A uniform spherical shell of mass M and radius R rotates about a vertical axis on frictionless bearings as shown in figure 5 157 A massless cord passes around the equator of the shell over a pulley of rotational inertia I and radius r and i attached to a small object of mass m falling under gravity Neglect all frictions find the speed of the object after it ha fallen a distance h from rest Ans 2gh 71 2 M R Figure 5 157 m

A F A D 2 B FA D The equation of state for a gas is P where P V and 0 are pressure volume and absolute temperature respectively while a and R are constants The dimensions of a are A M L5T 2 B ML5T 2 a RO V V 3 2 C ML 5T D ML 2T 2 fa and h shall be

Read the following statements and Identify the correct statement s A A choice of change of different units change the number of significant digits B To remove ambiguities in determining the number of significant figures the best way is to report the measurement in scientific notation C Solid angle made by a hemisphere at its centre is 47 steradian A Only A is true B Only B is true C Both A and B are true

57 A cube of mass m and side a is moving along a plane with constant speed vo as shown in figure The magnitude of angular momentum of the cube about z axis would be mvob a 2 c mvo b b 7 30 b 3mvob 2 d None of these

A vehicle of mass m is moving on a rough horizonta road with momentum p If the coefficient of friction between the tyres and the road be u then the stopping distance is a c P 2 mg P 211 b d 20 2 mg p 2 m g

34 Tellurometer a type of EDM uses which of the following waves Radio waves RE

A motor car is travelling at 60 m s on a circular 37 road of radius 1200 m It is increasing its speed at the rate of 4 m s The acceleration of the car is 1 3 m s 2 4 m s 3 5 m s 4 7 m s A choke coil is connected to an ac source of 38 1 3 m s 3 5 m s 60 m s 1200 m f 4 m s 2 4 m s 4 7 m s 50 T me 3

The displacement time x t graph of two moving objects A and B are shown in the figure Choose the incorrect statement A B V t A is moving with constant velocity B is moving with increasing speed The acceleration of B may be constant A is moving with non zero constant

11 A uniform rod of mass m is at rest on a smooth vertical and rough horizontal surface 0 5 as shown in the figure The frictional force acting on it is 1 3 mg 2 3 mg 3 60 2 mg 2 mg 4 24 12 2 2

Determine the speed of 350 kg roller coaster car at C if it is launched at B with a speed just sufficient for it to round the top of the loop at C without leaving the track The radius of curvature at C is Pc 15 m 35 m

Q A long current wire is bent in the shapes shown in Fig 4652 Fig 4E 52 a b and c The circular path portion has radius R Find the magnetic induction at the centre of the Circular segment K BI O TE AL B TAP O 12 9 a AXE Fig 4E 52

Question No 2 View in English Two concentric circular loops of radii 7 cm and 2 14 cm are placed in the Y Z plane as shown in the figure The magnetic moment of this loop system is O 55 x 10 3 Am 55 10 Am O 33 10 3 Am O 33 x 103 Am 10 A 5A

A ring of mass m and radius r is made of an insulting material carries uniformly distributed charge Initially it rests on a frictionless horizontal tabletop with its plane vertical The charge on the ring such that it starts rolling on entering completely into the region of the magnetic field is mo then find the value of N rB m r

horizontal dest 95 A projectile is thrown at an angle 9 such that it is just able to cross a vertical wall at its highest point as shown in the figure The angle 0 at which the projectile is thrown is given by O o 10x2 3 4 10 10 a tan e tan Vo 3 33 3 H H b tan 3 d tan st 20 t Mh vd mv 4t 8 6 1 t 40 St 3 2 40 2

v v i v j is in an electric field E E k If 20 is initial de Broglie wavelength of electron its de Broglie wave length at time t is given by e E t m v 20 e E 1 2 20 n v e E BOBA JEE Main JEE January Sep 2020 Bookle Eng01

3 Assertion Inertia is the property by virtue of which the body is unable to change by itself the state of rest only Reason The bodies do not change their state unless acted upon by an unbalanced external force

The value of resistor R as shown in the given circuit is such that the power developed in the resistor R is maximum at steady state Find the maximum charge in C stored on the capacitor 602 wwwwwww 202 www

9 In the path of a beam converging towards a point on screen a glass plate of thickness t is placed The convergence point will shift by u refractive index of material of slab 1 t 3 t 1 u 1825 14 4

14 A wire has resistance 12 It is bent in the form of a circle The effective resistance between the two points on any diameter is equal to b 6 Q a 120 c 32 du current i is flowing through a conductor of when d 242 lent

Fig 4 1 is a ray diagram representing two rays passing through a converging lens B a State which of the labelled points is a principal focus of the lens b State which of the distances BX XY YZ or XZ is the focal length of the lens On Fig 4 1 draw another ray from point A to locate the image of point A Label this image 1 d On the ray diagram in Fig 4 1 the refraction is shown occurring at the centre line of the lens 1 Mark 1 Mark 3 Marks