Question

The relation between an A.C. voltage source and time in SI units is:
$V=120\sin \left(100\pi t\right)\cos \left(100\pi t\right)$ volt value of peak voltage and frequency will be respectively:

• A. $120$ volt and $100Hz$
• B. $\frac{120}{\sqrt{2}}$ volt and $100Hz$
• C. $60$ volt and $200Hz$
• D. $60$ volt and $100Hz$

Answer 1

Answer: (D)

$60$ volt and $100Hz$

The relation between an A.C voltage source and time is given by

$V=120sin\left(100\pi t\right).cos\left(100\pi t\right)$

$V=60sin\left(200\pi t\right)$ (as we know $2sin\theta .cos\theta =sin2\theta$)

The value of peak voltage is $V_0=60V$

The frequency, $\omega =2\pi f=200\pi$

$f=100Hz$

The correct option is D.