| Class XII |
Physics |
Physics Part-I |
7 |
transformer may have an efficiency of more than 95%. Combining Eqs. (7.33) and (7.34), we have ip v s N s i = v = N (7.35) s p p Since i and v both... |
|
| Class XII |
Physics |
Physics Part-I |
7 |
Physics design of the core or the air gaps in the core. It can be reduced by winding the primary and secondary coils one over the other. (ii) Resis... |
|
| Class XII |
Physics |
Physics Part-I |
7 |
(rms) current and is donoted by I: i I = m = 0.707im Similarly, the rms voltage is defined by v V = m = 0.707vm We have P = IV = I R 3. An ac volta... |
|
| Class XII |
Physics |
Physics Part-I |
7 |
wattless current. 7. The phase relationship between current and voltage in an ac circuit can be shown conveniently by representing voltage and curr... |
|
| Class XII |
Physics |
Physics Part-I |
7 |
ω 0L 1 Quality factor Q Dimensionless Q = = for a series R ω0 C R RLC circuit. Power factor Dimensionless = cos , is the phase difference between v... |
|
| Class XII |
Physics |
Physics Part-I |
7 |
not RC R C VR+ V C since VCis /2 out of phase of V R 6. Though in a phasor diagram, voltage and current are represented by vectors, these quantitie... |
|
| Class XI |
Fine Art |
An Introduction to Indian A... |
8 |
e t a a ed i a i a r d i 6 u m d e h r d g e n l i r e r t a s s s w f m a o e r r e a B 6 B t n a gt w r i b a o u p o t d t e r o d v o g s m u s... |
|
| Class XII |
Physics |
Physics Part-I |
7 |
2026-27 Physics EXERCISES 7.1 A 100 W resistor is connected to a 220 V, 50 Hz ac supply. (a) What is the rms value of current in the circuit? (b) W... |
|
| Class XII |
Physics |
Physics Part-I |
7 |
LC combination is zero at the resonating frequency. Reprint 2026-27 |
|
| Class XII |
Physics |
Physics Part-I |
8 |
Chapter Eight ELECTROMAGNETIC WAVES 8.1 I NTRODUCTION In Chapter 4, we learnt that an electric current produces magnetic field and that two current... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
spectrum of electromagnetic waves, (1831 – 1879) Born in stretching from grays (wavelength ~10 –12m) to long Edinburgh, Scotland, 6 was among the g... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
centred L Maxwell did not agree symmetrically with respect to the wire [Fig. 8.1(a)]. From C with the idea (strongly S suggested by the symmetry, t... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
of the capacitor have an area A, and a total charge Q, the magnitude of the electric field E between the plates is (Q/A)/ e (see Eq. 2.41). The fie... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
P outside the plates [Fig. 8.1(a)] is the same as at a point M just shaped surface with inside, as it should be. The current carried by conductors ... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
(8.6) and is known as Ampere-Maxwell law. In all respects, the displacement current has the same physical effectsastheconductioncurrent.Insomecases... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
field changing with time gives rise to a magnetic field, is the symmetrical counterpart, and is * They are still not perfectly symmetrical; there a... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
fields thus regenerate each other, so to speak, as the wave propagates through the space. The frequency of the electromagnetic wave naturally equal... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
be shown from Maxwell’s equations that electric D magnetic waves, sent and magnetic fields in an electromagnetic wave are O perpendicular to each o... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
is the angular frequency. k is the magnitude of the wave vector (or propagation vector) k and its direction describes the direction of propagation ... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
velocity of light depends on electric and magnetic properties of the medium. We shall see in the next chapter that the refractive index of one medi... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
Example 8.2 The magnetic field in a plane electromagnetic wave is i e given by –7 T sin (0.5×10 x+1.5×10 t). e n By= (2 × 10 ) o i (a) What is the ... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
these different types of electromagnetic waves, in 208 order of decreasing wavelengths. Reprint 2026-27 Electromagnetic Waves FIGURE 8.4 The electr... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
, also absorb 2 3 infrared waves). After absorption, their thermal motion increases, that is, they heat up and heat their surroundings. Infrared la... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
about 40 – 50 km. UV light in large quantities has harmful effects on humans. Exposure to UV radiation induces the production of more melanin, caus... |
|
| Class XII |
Physics |
Physics Part-I |
8 |
ABLE 8.1 D IFFERENT TYPES OF ELECTROMAGNETIC WAVES Type Wavelength range Production Detection Radio > 0.1 m Rapid acceleration and Receiver’s aeria... |
|