Frequent Physics Questions

Problem: When a photon is emitted from an atom, the atom recoils. The kinetic energy of recoil and the energy of the photon come from the difference in energies between the states involved in the transistion. Suppose, a hydro ...

A plank of mass 10 kg rests on a smooth horizontal surface . Two blocks A and B of masses m = 2kg and m = 1 kg resp. lie at a distance of 3 m on the plank as shown in the figure . The friction coeff. b/w the blocks and plank ...

A thin spherical shell of total mass M and radius R is held fixed. There is a small hole in the shell. A mass m is released from rest at a distance R from the hole along a straight line that passes through the hole and also t ...

A rope ladder with a length L carrying a man of mass m at its end is attached to the basket of a balloon with a mass M. The entire system is in equilibrium in the air. Find the work the man should do to climb into the basket. ...

A tree trunk in form of a cylinder of radius R lies on a horizontal field. A lazy grasshopper wants to jump over it. What minimum launching speed will suffice for it? Assume that the air resistance is negligible and that the ...

A rod OA of mass 4 kg is held in horizontal position by a massless string AB as shown in the figure,Length of the rod is 2 m .Find : a.tension in the string b.net force exerted gy the hingre on the rod *Image* ...

A drinking straw of length 3a/2 and mass 2m is placed on a square table of side 'a' parallel to one of its sides such that one third of its length extends beyond the table.An insect of mass m/2 lands on the inner end ...

A parallel plate capacitor of area 60cm^2 and separation 3mm is charged initially at 90 micro coulomb. If the medium between the plates get slightly conducting and the plate loses charge initially at the rate of 2.5 *10^-8 C ...

a block of mass m produces an extension of 9cm in an elastic spring of length 60cm when it is hung by it, and the system is in equilibrium. the spring is cut in two parts of 40cm and 20cm lengths, the same block hangs in equi ...

n identical waves each of intensity I interfere with each other.The ratio of maximum intensities if the interference is (i) coherent and (ii) incoherent is a.n^2 b.1/n c.1/n^2 d.n ...

The horizontal and vertical distances traveled by a particle in time t are given by x = 6t and y=8t-5t^2 . If g=10m/sec^2 , then the initial velocity of the particle is a) 8 m/sec b) 10 m/sec c) 5 m/sec d) zero ...

Why is it that we never consider internal forces while considering a particular system? Explain in detail. ...

1) Explain why it easier to pull the roller than to push it with the help of a diagram. 2)A horse cannot pull an empty cart in space. Why is it so? Explain in some detail. ...

1) Explain why it easier to pull the roller than to push it with the help of a diagram. 2)A horse cannot pull an empty cart in space. Why is it so? Explain in some detail. ...

I have two questions of friction : 1)Why is the coefficient of friction never equal to 1 or 0,but always between 0 and 1? What will happen if the coefficient of friction is EXACTLY 0 or 1? Please explain in some detail. 2)Pol ...

The device used for measuring potential difference is known as _____________. a) potentiometer b) ammeter c) galvanometer d) voltmeter ...

what is the order of human mass ...

The velocity-time graph of a body is shown in figure. The displacement covered by the body in 8 seconds is *Image* a) 10 m b) 9 m c) 24 m d) 30 m ...

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infinite number of straight wires each carrying current i are equally placed as shown in the fig. adjacent wires have curent in opposite direction. net magnetic field at point p is *Image* a. μi ln2/4π 3 a k b. μi ln4/4π ...

1.Determine the magnetic field at the centre of the current carrying wire arrangement shown in the figure. the arrangement extends to infinity. the wires joining the successive squares are along the line passing through the c ...

What is the magnitude of magnetic field at centre O of loop of radius √2 m made of uniform wire when a current of 1 A enters in the loop and taken out of it by two long wire as shown ...

Law of reflection in irregular surface is a) obeyed b) not obeyed c) depends on the material of the surface d) none of these ...

A disk of radius r,mass m which has a charge q distributed uniformly over it is rotating in a magnetic field B about it's axis with an angular speed ω.Find the ratio of magnetic moment and angular momentum. ...

A coil of area A = 0.5 m2 is situated in a uniform magnetic field B = 4.0 wb/m2 and area vector makes an angle of 60o with respect to the magnetic field as shown in figure. The value of the magnetic flux through the area A wo ...

A car weighing 200 kg accelerates from rest at the rate of 5 m/s2. Find its momentum after 10 s. a) 10000 b) 1000 c) 500 d) none of them ...

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shadow is formed by ______________ objects transparent translucent both of them none of these Your Answer b Correct Answer d How can the answer be none of them ? Transculent objects form a light shadow and transparent objects ...

A circular loop of radius R carries a current I.Another circular loop of radius r(<<R) carries a current i and is placed at the centre of the larger loop.The planes of the two circles are at right angle to each other.Fi ...

Describe the energy of a car driving up a hill. a) entirely kinetic b) entirely potential c) both kinetic and potential d) gravitational ...