Basic Physics Questions and Answers

What is the magnitude of the acceleration of a box of mass 25 kg if it slides down a frictionless slope that is inclined 21 degrees above the horizontal 2 10 m s 0 50 m s 5 00 m s 3 51 m s

15 A thin semicircular ring of radius r as shown in figure as a positive charge q distributed uniformly over it The net field E at the centre O is a C aj 2n or q 1 2 r b d q 2 4 or q 2 C ISANG

16 The decreasing order of wavelength of infrared microwaves ultraviolet and gamma rays is a infrared microwaves ultraviolet gamma rays b microwaves infrared ultraviolet gamma rays c gamma rays ultraviolet infrared microwaves d microwaves gamma rays infrared ultraviolet

An organ pipe P closed at one end vibrating in its first overtone and another pipe P2 open at both ends vibrating in its third overtone are in resonance with a given tuning fork The ratio of the length of P to that of P2 is uestion Type Single Correct Type 1 2 3 8 3 3 8 1 2

4 WHICH OF THE FOLLOWING PHYSICAL QUANTITIES IS THE ODD ONE OUT OMAGNETIC FLUX

36 An electron moves with speed 2 x 105 ms 1 along the positive x direction in the presence of a magnetic induction B 1 41 3k tesla The magnitude of the force experienced by the electron in newton is charge on the electron 1 6 x 10 19 C 1 1 18 x 10 13 2 1 28 x 10 13 3 1 6 10 13 4 1 72 x 10 13

A sound wave is propagating in a medium with bulk modulus 1 5 105 N m and the pressure equation 3 is given by p 6 10 e x 7t where x is in meter t in second p in N m The volumetric strain at x 7m and t 1sec is given by a x 10 8 Fill a in OMR sheet

Two point sound sources S and S emitting sound of wavelength are kept separated by a distance 2 as shown A detector is moved along the line shown Find the number of minimas observed by the detecto Assume D 2 S A S 72 2 7

A small metallic sphere of mass m is suspended from the ceiling of a car accelerating on a horizontal road with constant acceleration a The tension in the string attached with metallic sphere is 1 mg 2 m g a 3 m g a 4 m g a

In a plane electromagnetic wave the directions of electric field and magnetic field are represented by kand 21 23 respectively What is the unit vector along direction of propagation of the wave JEE Main 2020 September 2 1 k 1 3 1 4 4 21 5 A plane electromagnetic wave has frequency of 2 0 10 0 Hz and its energy density is 1 02 x 10 8 J m in vacuum The amplitude of the magnetic field of the 1 4 o wave is close to 9 10 Nm C and speed of light 3 108 ms JEE Main 2020 September 1 110nT 2 140 nT

As shown in figure there are two sources S S producing progressive waves y 10 sin2 t 2x X and y 5 os 21 respectively and A is moving with constant velocity 5 m s Then find the resultant amplitude of the wave where A would be at t 3 s S 30 m 1 40 m A 5m sec

Two positive charges each of charge q are kept at a 0 and a 0 A negative charge is left from position 0 a then negative charge will perform Oscillatory motion Simple harmonic motion Will come to rest at centre Will continue moving along negative y axis

If electric field is zero at a point then electric potential V at that point Must be zero May be non zero May be zero Both 2 and 3

The magnetic induction at a point P which is at the distance of 4 cm from a long current carrying wire is 10 3 T The field of induction at a distance 12 cm from the current will be 1990 3 33 10 4 T 1 11 10 4 T 33 10 3 T

Two toroids 1 and 2 have total number of turns 200 and 100 respectively with average radii 40 cm and 20 cm respectively If they carry same current i the radio of the magnetic fields along the two loops is Odisha NEET 2019 1 1 4 1 2 1

Q 26 An inductor coil capacitor and an A C source of rms voltage 24 V are connected in series When the frequency of the source is varied a maximum rms current of 6 0 A is observed If this inductor coil is connected to a battery of emf 12 V and of internal resistance 4 92 the current will be Amp

2 20 If the zero of the vernier lies on the right hand side and fourth division coincide with the main scale division when the jaws are in contacts so the correction will be 1 0 04 cm 3 0 04 cm 2 0 06 cm 4 0 06 cm

The position time graph of a ball of mass 0 05 kg is given in the diagram The magnitude of net impulse received by the ball just after five seconds is x cm 2 Zero 3 10 3 kg m s A 5 x 10 kg m s 1 5 x 10 3 kg m s 5 t s

A student measures the period of oscillation of a simple pendulum in successiv measurements the reading turn out to be 1 98 s 1 99 s 2 06 s 2 08 s and 1 95 s A more accurate way to write the measurement with error is 2 0 0 1 s 2 03 0 06 s 2 0 0 06 s 2 03 0 1 s

Consider the following statements A and B and identify the correct answer A A zener diode is connected in reverse biss when used as a voltage regulator B The potential barrier of p n junction lies between 0 1 V to 0 3V 1 A is incorrect but B is correct A and B both are curren A and B both are incorrect 2 1 HIPE

Example 1 3 The moon is at a distance of 3 84x108 m from the Earth If viewed from two diametrically opposite points on the Earth the angle subtended at the moon is 1 54 What is the diameter of the Earth

A block of mass m is kept on a rough horizontal surface having coefficient of friction of 0 5 A horizontal force is applied on the block but the block remains at rest The maximum contact force exerted by the surface on the block can be mg 2 5 mg 2 3 mg 2 mg

An arrangement of three parallel straight wires placed perpendicular to plane of paper carrying same current I along the same direction as shown in figure Magnitude of force per unit length on the middle wire B is given by d B d A O 90 NEET 2017 2 01 d C

A coil of one turn is made of a wire of certain length and then from the same length a coil of two turns is made If the same current is passed in both the cases then the ratio of the magnetic inductions at their centres will be 1998 4 1 1 4 2 1

A block of mass m is placed on a smooth wedge of inclination The whole system is accelerated horizontally so that the block does not slip on the wedge The force exerted by the wedge on the block g is acceleration due to gravity will be 1 mg cos 0 2 mg sin 3 mg 4 mg cos 0

A bob of mass 0 2 kg hung from the ceiling of a room by a string 1 m long is set into oscillation The speed of the bob at its mean position is 2 m s 1 If the string is cut when the bob is at a point between its extreme and mean position then the trajectory of the bob is Straight line Parabola Circle Ellipse

A ball is thrown vertically upwards with initial velocity 30 m sec What will be its postion vector at time t 5 sec taking origin at the point of projection vertical up as positive y axis and horizontal as x axis a 0 25 b 0 20 c 0 45 d 0 5

3 B Ho ri 2k 4t R 4 B Mo ni 2k 4t R Re AIPMT 2015 A rectangular coil of length 0 12m and width 0 1m having 50 turns of wire is suspended vertically in a uniform magnetic field of strength 0 2 Weber m The coil carries a current of 2 A If the plane of the coil is inclined at an angl of 30 with the direction of the field the torqu required to keep the coil in stable equilibrium will be 1 0 12 Nm 3 0 20 Nm 2 0 15 Nm 4 0 24 Nm

Two spherical stars A and B emit blackbody radiation The radius of A is 400 times that of B and A emits 104 times the power emitted from B The ratio AA of their wavelengths and 2 at which the peaks occur in their B respective radiation curves is

If the weight of a body immersed in a fluid exceeds the buoyant force then the body will a rise b c until its weight equals the buoyant force tend to move downward and it may finally sink float hne none of the above

3 Adiabatic cooling causes rising air masses to a absorb moisture from Earth s surface b release precipitation c change the direction of the El Ni o current d flow toward the equator from the poles

A floating body is said to be in a state of stable equilibrium when its metacentric height is zero when the metacentre is above the centre of gravity when the metacentre is below the centre of gravity only when its centre of gravity is below its centre of buoyancy CS 95 a b c d

A conduction sphere S of radius R is placed in contact of another sphere of radius 2R and charge Q The change in mass sphere S is equal to ifratio for electron is P A 2Q 3P B 2Q 3P C 3P D Zero

Two circular coils 1 and 2 are made from the same wire but the radius of the 1st coil is twice that of the 2nd coil What potential difference in volts should be applied across them so that the magnetic field at their centres is the same 2006 2 3

D out of which ONLY ONE option is correct 1 A T shaped rod with its plane lying on a smooth horizontal surface is being pulled without rotation by a constant horizontal force F as shown in the figure The two straight rods have equal lengths and equal masses Then the value of angle 0 is A B C D tan 2 0 60

A small mass m starts from rest at top and slides down the smooth surface of a solid sphere of radius R The angle of radius vector of the mass with respect to the vertical when it leaves the surface of the sphere is nearly O 90 O 60 37 48

The accleration of free fall at a planet is determined by timing the fall of a steel ball photo electrically The ball passes B and Cat time t and t after release from A The accleration of free fall is given by Nof AP be Light beam D Motoelectric opl

An infinite number of charges each equal to Q are placed along the X axis at X 4 X 8 and so on The potential at the point X 0 due to ne of charges is 20 1 4T ED 1 20 2 3A ED 1Q

A uniformly charged and infinitely long line having a linear charge density 2 is placed at a normal distance y form a point O Consider a sphere of radius R with O as centre and R y Electric flux through the surface of the sphere is A zero C 2 22 R y B 2AR D 2 R

PHYS TRIC A charge q is placed at the centre of the open end of a cylindrical vessel The flux of the electric field vessel is through the surface of the A zero 9 480 B q 2 D 2q Laurface of radiu R

The velocity v of moving object varies with displacement x as v x 2x then the acceleration x 2m is 48ms 2 Clear Respons

Es 2 kg and spring constant is 100 N m In the given position the spring is at its natural length If the string In the given figure all the surfaces are smooth The spring and string are massless The mass of each block EF is burnt then find the maximum compression of the spring from its natural length E F A B 0 45 m

The moment of inertia of a rectangular lamina of mass m length l and width b about an axis passing through its centre of mass perpendicular to its diagonal and lies in the plane b 12 m 4 b4 12 b A m C m b4 6 b B D none of these

Charge q is uniformly spread on a thin ring of radius R The ring rotates about its axis with a uniform frequency f Hz The magnitude of magnetic induction at the center of the ring is Mains 2011 2010 Hogf 2 R

10 The magnetic vector potential inside an infinitely long solenoid having no number of turns of wire per unit length and carrying a current I at a distance r from the axis of the solenoid is A HonoIr 2 g where g is a unit vector in the 0 direction in cylindrical coordinates Calculate B r Ans Honol z

A cylinder of radius R and length L is placed in a uniform electric field E parallel to the axis The total flux for the cylinder surface of the cylinder is given by B 2 R E A 2TR E TR R E D Zero

Consider two concentric spherical surfaces S with radius a and S with radius 2a both centered on the origin There is a charge q at the origin and no other charges Compare the flux through S with the flux o through S A 4 C b d B 26 D 6 92

A spherical gas cloud of radius Rhas total charge Q distributed uniformly in its volume A charged particle having charge q and mass mis projected from its centre with speed v Assume that the cloud doesn t exert gravitational force or any resistive force on the particle The minimum value of v so that the particle is able to escape the cloud is nQq where nis 4 mR

C 480 In a region of space the electric field is given by 8 4j 3k The electric flux surface of area of 100 units through a in x y plane is A 800 units C 400 units B 300 units D 1500 units of Jongth I is

11 Problem 9 You throw an object up with a speed of voy 2 m s from a height of y 25 m 33 Part a How long in seconds does it take for the object to reach the ground 1 3 491 sin cotan stan cos asin tan T acos E 7 4 8 9 5 6 HOME