154695 Magnetic flux passing through a coil is initially $4 \times 10^{-4} \mathrm{~Wb}$. It reduces to $10 \%$ of its original value in ' $t$ ' second. If the e.m.f. induced is 0.72 $\mathbf{m V}$ then ' $t$ ' in second is

154696 A helicopter rises vertically with a speed of 100 $\mathrm{ms}^{-1}$. If helicopter has length $10 \mathrm{~m}$ and horizontal component of earth's magnetic field is $5 \times 10^{-3} \mathrm{Wbm}^{-2}$, then the induced emf between the tip of nose and tail of helicopter is

154699 A solenoid has 2000 turns wound over a length of $0.30 \mathrm{~m}$. The area of its cross-section is $1.2 \times 10^{-3} \mathrm{~m}^{2}$. Around its central section, a coil of 300 turn is wound. If an initial current of $2 \mathrm{~A}$ in the solenoid is reversed in $0.25 \mathrm{~s}$, then the emf induced in the coil is

154700 A rectangular coil of 300 turns has an average area of $25 \mathrm{~cm} \times 10 \mathrm{~cm}$. The coil rotates with a speed of 50 cps in uniform magnetic field of strength $4 \times 10^{-2} \mathrm{~T}$ about an axis perpendicular to the field. The peak value of the induced emf is (in volt) :

154695 Magnetic flux passing through a coil is initially $4 \times 10^{-4} \mathrm{~Wb}$. It reduces to $10 \%$ of its original value in ' $t$ ' second. If the e.m.f. induced is 0.72 $\mathbf{m V}$ then ' $t$ ' in second is

154696 A helicopter rises vertically with a speed of 100 $\mathrm{ms}^{-1}$. If helicopter has length $10 \mathrm{~m}$ and horizontal component of earth's magnetic field is $5 \times 10^{-3} \mathrm{Wbm}^{-2}$, then the induced emf between the tip of nose and tail of helicopter is

154699 A solenoid has 2000 turns wound over a length of $0.30 \mathrm{~m}$. The area of its cross-section is $1.2 \times 10^{-3} \mathrm{~m}^{2}$. Around its central section, a coil of 300 turn is wound. If an initial current of $2 \mathrm{~A}$ in the solenoid is reversed in $0.25 \mathrm{~s}$, then the emf induced in the coil is

154700 A rectangular coil of 300 turns has an average area of $25 \mathrm{~cm} \times 10 \mathrm{~cm}$. The coil rotates with a speed of 50 cps in uniform magnetic field of strength $4 \times 10^{-2} \mathrm{~T}$ about an axis perpendicular to the field. The peak value of the induced emf is (in volt) :

154695 Magnetic flux passing through a coil is initially $4 \times 10^{-4} \mathrm{~Wb}$. It reduces to $10 \%$ of its original value in ' $t$ ' second. If the e.m.f. induced is 0.72 $\mathbf{m V}$ then ' $t$ ' in second is

154696 A helicopter rises vertically with a speed of 100 $\mathrm{ms}^{-1}$. If helicopter has length $10 \mathrm{~m}$ and horizontal component of earth's magnetic field is $5 \times 10^{-3} \mathrm{Wbm}^{-2}$, then the induced emf between the tip of nose and tail of helicopter is

154699 A solenoid has 2000 turns wound over a length of $0.30 \mathrm{~m}$. The area of its cross-section is $1.2 \times 10^{-3} \mathrm{~m}^{2}$. Around its central section, a coil of 300 turn is wound. If an initial current of $2 \mathrm{~A}$ in the solenoid is reversed in $0.25 \mathrm{~s}$, then the emf induced in the coil is

154700 A rectangular coil of 300 turns has an average area of $25 \mathrm{~cm} \times 10 \mathrm{~cm}$. The coil rotates with a speed of 50 cps in uniform magnetic field of strength $4 \times 10^{-2} \mathrm{~T}$ about an axis perpendicular to the field. The peak value of the induced emf is (in volt) :

154695 Magnetic flux passing through a coil is initially $4 \times 10^{-4} \mathrm{~Wb}$. It reduces to $10 \%$ of its original value in ' $t$ ' second. If the e.m.f. induced is 0.72 $\mathbf{m V}$ then ' $t$ ' in second is

154696 A helicopter rises vertically with a speed of 100 $\mathrm{ms}^{-1}$. If helicopter has length $10 \mathrm{~m}$ and horizontal component of earth's magnetic field is $5 \times 10^{-3} \mathrm{Wbm}^{-2}$, then the induced emf between the tip of nose and tail of helicopter is

154699 A solenoid has 2000 turns wound over a length of $0.30 \mathrm{~m}$. The area of its cross-section is $1.2 \times 10^{-3} \mathrm{~m}^{2}$. Around its central section, a coil of 300 turn is wound. If an initial current of $2 \mathrm{~A}$ in the solenoid is reversed in $0.25 \mathrm{~s}$, then the emf induced in the coil is

154700 A rectangular coil of 300 turns has an average area of $25 \mathrm{~cm} \times 10 \mathrm{~cm}$. The coil rotates with a speed of 50 cps in uniform magnetic field of strength $4 \times 10^{-2} \mathrm{~T}$ about an axis perpendicular to the field. The peak value of the induced emf is (in volt) :