A step-down transformer is connected to main supply 200V to operate a 6V, 30W bulb. The current in primary is
(1) 3 A
(2) 1.5 A
(3) 0.3 A
(4) 0.15 A
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyA transformer has 100 turns in the primary coil and carries 8 A current. If input power is one kilowatt, the number of turns required in the secondary coil to have 500V output will be
(1) 100
(2) 200
(3) 400
(4) 300
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyThe potential difference V and the current i flowing through an instrument in an ac circuit of frequency f are given by volts and I = 2 sin ωt amperes (where ω = 2πf). The power dissipated in the instrument is
(1) Zero
(2) 10 W
(3) 5 W
(4) 2.5 W
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyA generator produces a voltage that is given by V = 240 sin 120 t, where t is in seconds. The frequency and r.m.s. voltage are
(1) 60 Hz and 240 V
(2) 19 Hz and 120 V
(3) 19 Hz and 170 V
(4) 754 Hz and 70 V
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyThe peak value of an alternating e.m.f. E is given by is 10 volts and its frequency is 50 Hz. At time , the instantaneous e.m.f. is
(1) 10 V
(2)
(3) 5 V
(4) 1 V
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyIf a current I given by flows in an ac circuit across which an ac potential of has been applied, then the power consumption P in the circuit will be
(1)
(2)
(3)
(4) P = 0
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyA resistance of 20 ohms is connected to a source of an alternating potential, V = 220sin(100πt). The time taken by the current to change from its peak value to its r.m.s value will be:
1. 0.2 sec
2. 0.25 sec
3. 25 × 10–3 sec
4. 2.5 × 10–3 sec
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyAn alternating current of frequency ‘f’ is flowing in a circuit containing a resistance R and a choke L in series. The impedance of this circuit will be:
1. R + 2πfL
2.
3.
4.
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyA resistance of 300 Ω and an inductance of henry are connected in series to an ac voltage of 20 volts and a 200 Hz frequency. The phase angle between the voltage and current will be:
1.
2.
3.
4.
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyIn a region of uniform magnetic induction B = 10–2 tesla, a circular coil of radius 30 cm and resistance π2 ohm is rotated about an axis that is perpendicular to the direction of B and which forms a diameter of the coil. If the coil rotates at 200 rpm the amplitude of the alternating current induced in the coil is :
(1) 4π2 mA
(2) 30 mA
(3) 6 mA
(4) 200 mA
Prefer Books for Question Practice? Get NEETprep's Unique MCQ Books with Online Audio/Video/Text Solutions via Telegram Bot
NEET MCQ Books for XIth & XIIth Physics, Chemistry & Biology