NEET 2017 APRA

A rope is wound around a hollow cylinder of mass 3 kg and radius 40 cm. What is the angular acceleration of the cylinder if the rope is pulled with a force of 30 N?

A long solenoid of diameter 0.1 m has $$2 \times 10^4$$ turns per meter. At the centre of the solenoid, a coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to 0 A from 4 A in 0.05 s. If the resistance of the coil is $$10 \pi^2 Ω$$, the total charge flowing through the coil during this time is

The ratio of wavelengths of the last line of Balmer series and the last line of Lyman series is

Suppose the charge of a proton and an electron differ slightly. One of them is -e, the other is $$(e + \triangle e)$$. If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then $$\triangle e$$ is of the order of [Given mass of hydrogen $$m_h = 1.67 \times 10^{-27}$$ kg]

The given electrical network is equivalent to

A Carnot engine having an efficiency of $$\frac{1}{10}$$ as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is

In an electromagnetic wave in free space the root mean square value of the electric field is $$E_rms = 6 V/m$$. The peak value of the magnetic field is

Two Polaroids $$P_1 and P_2$$ are placed with their axis perpendicular to each other. Unpolarised light $$I_0$$ is incident on $$P_1$$. A third polaroid $$P_3$$ is kept in between $$P_1 and P_2$$ such that its axis makes an angle $$45^\circ$$ with that of $$P_1$$. The intensity of transmitted light through $$P_2$$ is

If $$\theta_1 and \theta_2$$ be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of dip $$\theta$$ is given by

A 250-Turn rectangular coil of length 2.1 cm and width 1.25 cm carries a current of $$85 \mu A$$ and subjected to a magnetic field of strength 0.85 T. Work done for rotating the coil by $$180^\circ$$ against the torque is