Q 1 :    

An alternating current at any instant is given by $i=[6+\sqrt{56}\sin (100\pi t+\frac{\pi }{3}\left)\right]A$. The rms value of the current is _______ A    [2024]

Q 2 :    

An alternating voltage $V\left(t\right)=220$ $\sin$ $100\pi t$ volt is applied to a purely resistive load of 50$\Omega$. The time taken for the current to rise from half of the peak value to the peak value is                [2024]

• 5 ms

   

• 3.3 ms

   

• 7.2 ms

   

• 2.2 ms

   

Q 3 :    

An alternating current is given by

$I=I_A \sin \omega t+I_B \cos \omega t$

The r.m.s. current will be          [2025]

• $\sqrt{I_A^2+I_B^2}$

   

• $\frac{\sqrt{I_A^2+I_B^2}}{2}$

   

• $\sqrt{\frac{I_A^2+I_B^2}{2}}$

   

• $\frac{|I_A+I_B|}{\sqrt{2}}$

   

Q 4 :    

An electric bulb rated as 100 W – 220 V is connected to an ac source of rms voltage 220 V. The peak value of current through the bulb is:          [2025]

• 0.64 A

   

• 0.45 A

   

• 2.2 A

   

• 0.32 A

   

Q 5 :    

An alternating current is represented by the equation, $i=100\sqrt{2} \sin (100 \pi t)$ ampere. The RMS value of current and the frequency of the given alternating current are          [2025]

• $100\sqrt{2} \mathrm{A}, 100 \mathrm{Hz}$

   

• $\frac{100}{\sqrt{2}} \mathrm{A}, 100 \mathrm{Hz}$

   

• 100 A, 50 Hz

   

• $50\sqrt{2} \mathrm{A}, 50 \mathrm{Hz}$

   

Q 6 :    

An ac current is represented as

$i=5\sqrt{2}+10 \cos (650 \pi t+\frac{\pi }{6}) \mathrm{Amp}$

The r.m.s. value of the current is          [2025]

• 20 Amp

   

• 100 Amp

   

• 10 Amp

   

• $5\sqrt{2} \mathrm{Amp}$