Question 1 :
Assertion(A): The possibility of an electric bulb fusing is higher at the time of switching on and off.<br/>Reason(R): Inductive effects produce a large current at the time of switch-on and switch-off. <br/>
Question 2 :
Two coils A and B have mutual inductance $2\times 10^{-2}$ henry. If the current in the primary is $i = 5\sin (10\pi t)$ then the maximum value of e.m.f. induced in coil B is:
Question 3 :
The horizontal component of the earth's magnetic field at a place is $3 \times 10 ^ { - 4 } T$and the dip is $\theta$ = $t a n ^ { - 1 }$ (4/3). A metal rod of length 0. 25 m placed in the north-south position is moved at a constant speed of 10 cm/s towards the east. The e.m.f induced in the rod will be:
Question 4 :
When we move a conductor of length l with speed V perpendicular to the magnetic field B the motional emf induced in the conductor will be
Question 5 :
Whenever, current is changed in a coil, an induced e.m.f. is produced in the same coil. This property of the coil is due to<br/>
Question 7 :
Two sources of equal emf are connected to an external resistance R. The internal resistances of two sources are $R_{ 1 }$ and $R_{ 2 }$($R_{ 2 }$>$R_{ 1 }$). If the potential difference across the source having internal resistance $R_{ 2 }$ is zero, then;
Question 8 :
Under what condition will the strength of current in a wire of resistance R be the same for connection is series and in parallel of n identical cells each of the internal resistance r? When
Question 11 :
Assertion(A): An inductor in a D.C. circuit opposes both a steady current and a changing current.Reason(R): Induced emf is generated only when the flux linked with the inductor remains unchanged.<br/>
Question 13 :
Foran inductorcoil $L = 0.04H$ then work done by source to establish a current of 5A in it is:-
Question 16 :
If $0.1J$ of energy is stored for the flow of current of $0.2A$ in an inductor, then its inductance value is:
Question 18 :
If coil is placed perpendicular to field lines then number of lines passing through coil are :
Question 21 :
Two identical coaxial coils $P$ and $Q$ carrying equal amount of current in the same direction are brought nearer. The current in
Question 22 :
A jet plane is travelling towards west at a speed of $1800\ km/h$. What is the voltage difference developed between the ends of the wing having a span of $25\ m$, if the Earth's magnetic field at the location has a magnitude of $5 \times {10}^{-4}\ T$ and the dip angle is $30^o$.
Question 23 :
A car moves up a plane road. The induced emf in the axle connecting the two wheels is maximum when it moves
Question 24 :
Through an inductance coil of $L = 0.2 H$, an ac current of 2 ampere is passed first with frequency $n_1$ and then with frequency $n_2$. The ratio of the maximum value of induced emf $\left ( e_1/ e_2 \right )$ in the coil, in the two cases is
Question 26 :
An ac generator consists of a coil of 200 turns, 100 cm in diameter. If the coil rotates at 500 rpm in a magnetic field of 0.25T, then the maximum induced emf
Question 27 :
Magnetic flux $\phi$ (in weber) linked with a closed circuit of resistance $10 \Omega$varies with time t (in second) as$\phi = 5{t^2} - 4t + 1$. The induced electromotive force in the circuit at t = 0.2 second is
Question 28 :
A straight line conductor of length $0.4\ m$ is moved with a speed of $ 7 ms^{-1} $ perpendicular to magnetic field of intensity of $0.9\ Wbm^{-2} . $ The induced emf across the conductor is :
Question 29 :
Assertion (A): Lenz's law is a violation of the lawof conservation of energy<br>Reason (R): Induced emf always oppose thechange in magnetic flux that has produced them<br>
Question 30 :
A coil of wire is placed in a changing magnetic field. If the number of turns in the coil is decreased, the voltage induced across the coil will
Question 31 :
A bar magnet is moved along the axis of a copper ring placed far away from the magnet. Looking from the side of the magnet, an anti-clockwise current is found to be induced in the ring. Which of the following may be true?
Question 32 :
A coil in a simple generator has 200 turns.Now the number of turns in the coil increases to 500. What will be its effect:
Question 33 :
Assertion: The self-inductance of a long solenoid is proportional to the area of cross-section and length of the solenoid.
Reason: Self inductance of a solenoid is independent of the number of turns per unit length.
Question 34 :
When rate of change of current in a circuit is unity, the induced emf is equal to<br/>
Question 35 :
Same current is flowing in two identical coaxial circular coils. On looking at the coils from a point at the centre between them, the current in one coil appears to be flowing in clockwise direction. If the two coils at displaced towards each other, then the value of current:
