1
JEE Main 2019 (Online) 10th April Evening Slot
+4
-1
A coil of self inductance 10 mH and resistance 0.1 $$\Omega$$ is connected through a switch to a battery of internal resistance 0.9 $$\Omega$$. After the switch is closed, the time taken for the current to attain 80% of the saturation value is: [take ln 5 = 1.6]
A
0.324 s
B
0.002 s
C
0.103 s
D
0.016 s
2
JEE Main 2019 (Online) 10th April Morning Slot
+4
-1
A transformer consisting of 300 turns in the primary and 150 turns in the secondary gives output power of 2.2 kW. If the current in the secondary coil is 10A, then the input voltage and current in the primary coil are :
A
220 V and 20 A
B
220 V and 10A
C
440 V and 5A
D
440 V and 20 A
3
JEE Main 2019 (Online) 8th April Evening Slot
+4
-1
A circuit connected to an ac source of emf e = e0sin(100t) with t in seconds, gives a phase difference of $$\pi$$/4 between the emf e and current i. Which of the following circuits will exhibit this ?
A
RC circuit with R = 1 k$$\Omega$$ and C = 1μF
B
RL circuit with R = 1k$$\Omega$$ and L = 1mH
C
RC circuit with R = 1k$$\Omega$$ and C = 10 μF
D
RL circuit with R = 1 k$$\Omega$$ and L = 10 mH
4
JEE Main 2019 (Online) 8th April Morning Slot
+4
-1
An alternating voltage v(t) = 220 sin 100 $$\pi$$t volt is applied to a purely resistance load of 50$$\Omega$$ . The time taken for the current to rise from half of the peak value to the peak value is :
A
5 ms
B
2.2 ms
C
3.3 ms
D
7.2 ms
EXAM MAP
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