1
COMEDK 2024 Morning Shift
+1
-0

Around the central part of an air cored solenoid of length $$20 \mathrm{~cm}$$ and area of cross section $$1.4 \times 10^{-3} \mathrm{~m}^2$$ and 3000 turns, another coil of 250 turns is closely wound. A current $$2 \mathrm{~A}$$ in the solenoid is reversed in $$0.2 \mathrm{~s}$$, then the induced emf produced is

A
$$1.32 \times 10^{-1} \mathrm{~V}$$
B
$$4 \times 10^{-1} \mathrm{~V}$$
C
$$1.16 \times 10^{-1} \mathrm{~V}$$
D
$$8 \times 10^{-2} \mathrm{~V}$$
2
COMEDK 2024 Morning Shift
+1
-0

A metallic rod of $$2 \mathrm{~m}$$ length is rotated with a frequency $$100 \mathrm{~Hz}$$ about an axis passing through the centre of the circular ring of radius $$2 \mathrm{~m}$$. A constant magnetic field $$2 \mathrm{~T}$$ is applied parallel to the axis and perpendicular to the length of the rod. The emf developed across the ends of the rod is :

A
800 $$\pi$$ volt
B
1600 $$\pi$$ volt
C
1600 volt
D
400 $$\pi$$ volt
3
COMEDK 2023 Morning Shift
+1
-0

The magnetic flux linked with a coil satisfies the relation $$\phi=\left(4 t^2+6 t+9\right) \mathrm{Wb}$$, where $$t$$ is time in second. The emf induced in the coil at $$t=2 \mathrm{~s}$$ is

A
22 V
B
18 V
C
16 V
D
40 V
4
COMEDK 2023 Evening Shift
+1
-0

One volt induced emf is produced in the secondary coil when the current through the primary coil is changed from $$3 \mathrm{~A}$$ to $$1 \mathrm{~A}$$ in 100 milliseconds. the mutual inductance of the two coil is:

A
0.5 H
B
0.25 H
C
0.005 H
D
0.05 H
EXAM MAP
Medical
NEET