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197 questions found · practise this subject as a set Show 20 · 50 per page

#	Question	Subject and topic	Difficulty
101	In a purely inductive AC circuit, the current:	Physics Alternating current	Medium
102	As the frequency of the AC supply increases, the reactance of a capacitor:	Physics Alternating current	Hard
103	A series LCR circuit has L = 0.1 H and C = 10 μF. Its resonant frequency is about:	Physics Resonance and power in AC circuits	Medium
104	At resonance in a series LCR circuit, the impedance is:	Physics Resonance and power in AC circuits	Easy
105	The power factor of a purely inductive circuit is:	Physics Resonance and power in AC circuits	Easy
106	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
107	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
108	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
109	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
110	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
111	A transformer works on the principle of:	Physics AC generator and transformer	Easy
112	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
113	Maxwell's displacement current through a surface is given by:	Physics Displacement current	Easy
114	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
115	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
116	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
117	A plane electromagnetic wave travels along the +x axis and its electric field oscillates along the y axis. Al…	Physics Displacement current	Hard
118	Which electromagnetic radiation has the shortest wavelength?	Physics Electromagnetic spectrum	Easy
119	Radar systems used for aircraft navigation mainly use:	Physics Electromagnetic spectrum	Easy
120	An FM station broadcasts at 100 MHz. What is the wavelength of its waves in air?	Physics Electromagnetic spectrum	Medium