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#	Question	Subject and topic	Difficulty
4961	The power factor of a purely inductive circuit is:	Physics Resonance and power in AC circuits	Easy
4962	A series circuit with R = 30 Ω and Z = 50 Ω is connected to a 200 V (rms) supply. The average power consumed …	Physics Resonance and power in AC circuits	Medium
4963	A choke coil is preferred to a resistor for reducing current in AC circuits because the choke:	Physics Resonance and power in AC circuits	Hard
4964	A transformer has 200 turns in the primary and 1000 turns in the secondary. If the primary voltage is 220 V A…	Physics AC generator and transformer	Easy
4965	An ideal step-down transformer gives 11 V and 4 A from a 220 V supply. The primary current is:	Physics AC generator and transformer	Medium
4966	A coil of 100 turns and area 0.02 m² rotates at 50 revolutions per second in a field of 0.1 T. The peak emf i…	Physics AC generator and transformer	Hard
4967	A transformer works on the principle of:	Physics AC generator and transformer	Easy
4968	In an AC generator, the induced emf in the rotating coil is maximum when the plane of the coil is:	Physics AC generator and transformer	Medium
4969	Maxwell's displacement current through a surface is given by:	Physics Displacement current	Easy
4970	A parallel-plate capacitor is being charged, and the current in the connecting wires is 1.5 A. What is the di…	Physics Displacement current	Easy
4971	The voltage across a 2 μF capacitor increases at a steady rate of 5000 V/s. What is the displacement current …	Physics Displacement current	Medium
4972	In a plane electromagnetic wave in vacuum, the peak electric field is 6 V/m. What is the peak magnetic field?	Physics Displacement current	Medium
4973	A plane electromagnetic wave travels along the +x axis and its electric field oscillates along the y axis. Al…	Physics Displacement current	Hard
4974	Which electromagnetic radiation has the shortest wavelength?	Physics Electromagnetic spectrum	Easy
4975	Radar systems used for aircraft navigation mainly use:	Physics Electromagnetic spectrum	Easy
4976	An FM station broadcasts at 100 MHz. What is the wavelength of its waves in air?	Physics Electromagnetic spectrum	Medium
4977	The ozone layer in the upper atmosphere protects living things mainly by absorbing:	Physics Electromagnetic spectrum	Medium
4978	An electromagnetic wave has a frequency of 10 GHz. What are its wavelength and the band it belongs to?	Physics Electromagnetic spectrum	Hard
4979	A spherical mirror has a radius of curvature of 24 cm. What is the magnitude of its focal length?	Physics Reflection by spherical mirrors	Easy
4980	The image formed by a convex mirror of a real object is always:	Physics Reflection by spherical mirrors	Easy