Physics NCERT Exemplar Solutions Class 11th Chapter Fifteen

Consider a uniform cubical box of side a on a rough floor that is to be moved by applying minimum possible force $F$ at $a$ point $b$ above its centre of mass (see figure). If the coefficient of friction is $\mu =0.4$ , the maximum possible value of $100*\frac{b}{a}$  for box not to topple before moving i

A circular conducting coil of radius 1 m being heated by the change of magnetic field B passing perpendicular to the plane in which the coil is laid. The resistance of the coil is 2μΩ. The magnetic field is slowly switched off such that its magnitude changes in time as B = (4/π) * 10?³ T [1 - ( t/100 )]. The energy dissipated by the coil before the magnetic field is switched off completely is E = _______ mJ.

The value of aluminium susceptibility is 2.2 * 10?. The percentage increase in the magnetic field if space within a current carrying toroid is filled with Aluminium is x/10?. Then the value of x is _______.

An electric bulb rated as 200 W at 100 V is used in a circuit having 200 V supply. The resistance R that must be put in series with the bulb so that the bulb delivers the same power is _______ Ω.

A body of mass 2 kg moving with a speed of 4 m/s, makes an elastic collision with another body at rest and continues to move in the original direction but with one fourth of its initial speed. The speed of the two body centre of mass is x/10 m/s. Then the value of x is _______ .

A pendulum bob has a speed of 3 m/s at its lowest position. The pendulum is 50 cm long. The speed of the bob, when the length makes an angle of 60° to the vertical will be _______ m/s. (g = 10 m/s²)

An inductor of 10 mH is connected to a 20 V battery through a resistor of 10 kΩ and a switch. After a long time, when maximum current is set up in the circuit, the current is switched off. The current in the circuit after 1 µs is x/100 mA. Then x is equal to _______. (Take e?¹ = 0.37)

A particle of mass 1 mg and charge q is lying at the mid-point of two stationary particles kept at a distance 2 m when each is carrying same charge q'. If the free charged particle is displaced from its equilibrium position through distance 'x' (x << 1m). The particle executes SHM. Its angular frequency of oscillation will be ______ * 10? rad/s if q' = 1 C.

In the reported figure, two bodies A and B of masses 200g and 800g are attached with the system of springs. Springs are kept in a stretched position with some extension when the system is released. The horizontal surface is assumed to be frictionless. The angular frequency will be _______ rad/s when k = 20 N/m.