Physics Ncert Solutions Class 12th

The pressure exerted by an electromagnetic wave of intensity I(W/M²) on a non-reflecting surface is (c is the velocity of light)

The distance of closest approach of an alpha particle fired towards gold nucleus with kinetic energy k is r₀. The distance of closest approach when the alpha particle is fired towards same nucleus with kinetic energy 4k will be

The current flow through the resistance in the given circuit is : (Cut-off voltage for both diodes is 0.7 V)

A n-p-n transistor can be used as

The output (X) of the logic circuit shown in figure will be

 

The angle between the plane of vibration and plane of polarization is

A circuit is made up of resistance 3 Ω and inductance 0.01 H. An alternating emf of 100 V at 50 Hz is connected, then the phase difference between the current and the emf in the circuit is

A 0.2 m long conductor carrying a current of 20 A is held perpendicular to magnetic field of 2.5 mT. The mechanical power required to move the conductor with speed 2 m/s perpendicular to length and field is

A long solenoid has 1000 turns per meter length of solenoid. A current of 3.2 A flow through it. The magnetic induction at the end of solenoid is

A radioactive sample decays by 63% of its initial value in 10s. It would have decayed by 50% of its initial value in :-