NEET-XII-Physics
38: Electromagnetic Induction
- #2-aWrite the SI units of a, b and c. (b) If the magnitudes of a, b and c are 0.20, 0.40 and 0.60 respectively, find the induced emf at t = 2 s.Ans : The dimensions of the quantities at2, bt, c and Ï• must be the same.
Thus, the units of the quantities are as follows:
`` a=\left(\frac{\,\mathrm{\,\varphi \,}}{{t}^{2}}\right)=\left[\frac{\,\mathrm{\,\varphi \,}/t}{t}\right]=\frac{\,\mathrm{\,Volt\,}}{\,\mathrm{\,s\,}}``
`` b=\left[\frac{\,\mathrm{\,\varphi \,}}{t}\right]=\,\mathrm{\,Volt\,}``
`` c=\left[\,\mathrm{\,\varphi \,}\right]=\,\mathrm{\,Weber\,}`` (b) The emf is written as:
`` E=\frac{d\varphi }{dt}`` = 2at + b = 2 × 0.2 × 2 + 0.4 (∵ a = 0.2, b = 0.4 and c = 0.6)
On substituting t = 2 s, we get
E = 0.8 + 0.4
= 1.2 V
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- #2-bIf the magnitudes of a, b and c are 0.20, 0.40 and 0.60 respectively, find the induced emf at t = 2 s.Ans : The emf is written as:
`` E=\frac{d\varphi }{dt}`` = 2at + b = 2 × 0.2 × 2 + 0.4 (∵ a = 0.2, b = 0.4 and c = 0.6)
On substituting t = 2 s, we get
E = 0.8 + 0.4
= 1.2 V
Page No 306: