Recently Active Physics Questions

the mean lives of a radioactive substance are 1620yrs for alpha emission and 405yrs for beta emission respectively. find out the time during which three-fourth of the sample will decay if it is decaying both by alpha emission ...

A magnetic dipole with moment \vec{\mu } rotates abt its axis whose Moment of Inertia is given as I, with a const. angular velocity \vec{\omega } . A const. magnetic field \vec{B_0 } is siwtched on at t=0. Magnetic field vect ...

A disc of mass m ,radius R is shown rolling on horz surface(having sufficient friction). Variation of electric fields with direction exist along its path as shown in figure *Image* charge on disc=Q 1)Find velocity of disc aft ...

in a gamma decay process, the internal energy of a nucleus of mass M decreases, a gamma photon of energy E and linear momentum E/c is emitted and the nucleus recoils Find the decrease in internal energy ...

A nucleus moving wid a vel. v emits @(alpha) particle .Let the velocities of the @ particle nd the remaining nucleus be v1 nd v2 nd their massess be m1 nd m2 .... (A)v,v1 nd v2 must be parallell to each other... (B)none of th ...

multiple choice... Q..A car of mass M is moving on a horizontal circular path of radius r.At an instant its speed is v & is increasing at the rate a............. (a)the acceleration of the car is towrds d centre of the path.. ...

Two masses m and 2m are attached to two ends of an ideal spring and the spring is in the compressed state. The energy of spring is 60 joule. If the spring is released, then A. the energy of both bodies will be same. B. energy ...

in a gamma decay process, the internal energy of a nucleus of mass M decreases, a gamma photon of energy E and linear momentum E/c is emitted and the nucleus recoils Find the decrease in internal energy ...

(Q) an electric filed E0i exits in a region nd a sphere of radius r is kept along the eletric field. V represents the potential, then which is one is correct 1. \frac{\partial }{\partial x} V is constant inside the sphere and ...

some more simple doubts- 1)find maximum excess pressure inside a thin walled steel tube of radius R and thickness r(<< R) so that tube wont rupture(breaking stress of steel s) 2)a beaker containing water is rigidly fixe ...

A uniform rod of length l is pivoted at pt. A.It is struck by horz. force which delivers an impulse J at distance x from pivot.For what value of x , the impulse delivered by pivot is equal to zero?????? ...

what is spallation ,nuclear reaction and induced radioactivity ?????how to identify these all ????? ...

a uniform disc of mass m and radius R is projected horizontally with velocity "Vo" on a rough horizontal surface so that it starts off with a purely sliding motion at t=0.After time "to" sec,it acquires a purely rolling motio ...

one face of an equiconvex lens of focal length 60 cm made of glass (μ=1.5) is silvered......does it behav lik a concave or covex mirror.....find effectiv f ...

A metal ring of mass m nd radius R is placed on a smooth horizontal table & is set rotating about its own axis in such a way tht each part of the ring moves with a speed v ...find the tension in d ring???????????? ...

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*Image* P.S the springs are attached to string and x=a ...

a person is in a room whose ceeiling and two adjacent walls r mirrors.....how many images r formed ...

U hav tied a weight W by a string as shown in d fig . Now u and ur frnd start pulling the string from both ends and try to straighten the string . What will be the tension in the string for wich the string completely becomes ...

An object is placed in front of a concave mirror of focal length 'f' as in figure find the size of image and its postion. *Image* The actual dbt is abt paraxial rays.We assumed this for our entire optics chapter,Well how is u ...

1) STATEMENT 1 : A charged particle is accelerated by a potential difference V . The electron enters perpendicular into a uniform magnetic field.The magnitude of angular momentum of the electron about centre of trajectory fol ...

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In the circuit show all the ammeters are ideal. 1) If the switch s is open find the current through all the ammeters and the pd accross the switch. 2)If the switch is closed find the current through all the ammeters . *Image* ...

A bird sitting in a wire cage which is hanging from a spring balance.if bird starts flying inside the cage,reading of spring balance will remain unchanged/be less/more than earlier? ...

A rod of mass 2m and length 2l is bent at its midpoint making 90° angle find the moment of inertia of the system about an axis passing through the point of bent symmetrically and making minimum angle of 45° with the plane o ...

*Image* A rod hinged at one end is released from the horizontal position as shown. When it becomes vertical its lower half separates without exerting any reaction at the breaking point. Then find the maximum angle θ made by ...

*Image* Extension to my question of 04-04-09.........find the velocity of the system after all possible perfectly inelastic collisions all the spheres have equal mass..... they have velocity whose magnitude is written over th ...

If a lens is immersed in a liquid( of different Refractive Index) the focal length wud change TRUE / FALSE ...

The speed of a 1.5*10^4 g navy fighter plane landing on a carrier is reduced 216 km/hr to rest by the plane's brakes and the cable arrester system . The arresting force provided by the plane's brakes is 600 kN . The arresting ...

A uniform bar AB of length 2 m. and mass 5 kg hanging freely frem a froctionless pivot at A is struck by a 25 gm bullet moving with a velocity of 500 m/s and making an angle of 30° with the horizontal . The bullet pierces th ...