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The figure shows a series LCR circuit with L = 10.0 H, C = 40 μF, R = 60 Ω connected to a variable frequency 240 V source, calculate
(i) the angular frequency of the source which drives the circuit at resonance,
(ii) the current at the resonating frequency,
(iii) the rms potential drop across the inductor at resonance.
Concept: Different Types of AC Circuits: AC Voltage Applied to a Series LCR Circuit
An alternative voltage given by V = 140 sin 314t is connected across a pure resistor of 50 Ω. Find
- The frequency of the source.
- The rms current is through the resistor.
Concept: Different Types of AC Circuits: AC Voltage Applied to a Resistor
Name the parts of the electromagnetic spectrum which is
used to treat muscular strain.
Write in brief, how these waves can be produced.
Concept: Electromagnetic Spectrum
Name the parts of the electromagnetic spectrum which is
used as a diagnostic tool in medicine.
Write in brief, how these waves can be produced.
Concept: Electromagnetic Spectrum
A capacitor has been charged by a dc source. What are the magnitude of conduction and displacement current, when it is fully charged?
Concept: Displacement Current
Name of physical quantity which remains same for microwaves of wavelength 1 mm and UV radiations of 1600 Å in vacuum.
Concept: Electromagnetic Spectrum
When an ideal capacitor is charged by a dc battery, no current flows. However, when an ac source is used, the current flows continuously. How does one explain this, based on the concept of displacement current?
Concept: Displacement Current
Answer briefly.
Give two uses of radio waves.
Concept: Electromagnetic Spectrum
Arrange the following electromagnetic radiation in the ascending order of their frequencies:
X-rays, microwaves, gamma rays, radio waves
Concept: Electromagnetic Spectrum
Write two uses of the following radiation.
Gamma rays
Concept: Electromagnetic Spectrum
A giant refracting telescope has an objective lens of focal length 15 m. If an eye piece of focal length 1.0 cm is used, what is the angular magnification of the telescope ?
Concept: Optical Instruments >> Simple Microscope or a Reading Glass
If this telescope is used to view the moon, what is the diameter of the image of the moon formed by the objective lens ? the diameter of the moon is 3.48 × 106 m and the radius of lunar orbit is 3.8 × 108m.
Concept: Optical Instruments >> Simple Microscope or a Reading Glass
The total magnification produced by a compound microscope is 20. The magnification produced by the eye piece is 5. The microscope is focussed on a certain object. The distance between the objective and eyepiece is observed to be 14 cm. If least distance of distinct vision is 20 cm, calculate the focal length of the objective and the eye piece.
Concept: Optical Instruments >> Simple Microscope or a Reading Glass
State the condition under which a large magnification can be achieved in an astronomical telescope.
Concept: Optical Instruments >> Telescope
Write the necessary conditions for the phenomenon of total internal reflection to
occur ?
Concept: Total Internal Reflection
Write the relation between the refractive index and critical angle for a given pair of optical media?
Concept: Total Internal Reflection
In the meterbridge experimental set up, shown in the figure, the null point ‘D’ is obtained at a distance of 40 cm from end A of the meterbridge wire. If a resistance of 10Ω is connected in series with R1, null point is obtained at AD = 60 cm. Calculate the values of R1 and R2.
Concept: Some Natural Phenomena Due to Sunlight
Draw a ray diagram showing the image formation by a compound microscope. Hence obtained expression for total magnification when the image is formed at infinity.
Concept: Optical Instruments >> Simple Microscope or a Reading Glass
Distinguish between myopia and hypermetropia. Show diagrammatically how these defects can be corrected.
Concept: Optical Instruments >> Simple Microscope or a Reading Glass
What is linearly polarized light?
Concept: Some Natural Phenomena Due to Sunlight
