Physics-
General
Easy
Question
Two circular coils A and B are facing each other as shown in figure. The current i through A can be altered
- there will be repulsion between A and B if i is increased
- there will be attraction between A and B if i is increased
- there will be neither attraction nor repulsion when i is changed
- attraction or repulsion between A and B depends on the direction of current. It does not depend whether the current is increased or decreased.
The correct answer is: there will be repulsion between A and B if i is increased
Related Questions to study
physics-
A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced currents in wires AB and CD are
A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced currents in wires AB and CD are
physics-General
physics-
In the shown AC circuit phase different between currents 
In the shown AC circuit phase different between currents
physics-General
physics-
The current I, potential difference 
across the inductor and potential difference 
across the capacitor in circuit as shown in the figure are best represented vectorially as
The current I, potential difference across the inductor and potential difference across the capacitor in circuit as shown in the figure are best represented vectorially as
physics-General
physics-
are the respective r.m.s. values of the time varying currents as shown in the four cases I, II, III and IV. Then identify the correct relations.
are the respective r.m.s. values of the time varying currents as shown in the four cases I, II, III and IV. Then identify the correct relations.
physics-General
physics-
In the circuit diagram shown, 
and R = 100 
. The effective current through the source is
In the circuit diagram shown, and R = 100 . The effective current through the source is
physics-General
physics-
The effective value of current 
is:
The effective value of current is:
physics-General
physics-
The direct current which would give the same heating effect in an equal constant resistance as the current shown in figure, i.e. the r.m.s. current, is
The direct current which would give the same heating effect in an equal constant resistance as the current shown in figure, i.e. the r.m.s. current, is
physics-General
physics-
The given figure represents the phasor diagram of a series LCR circuit connected to an ac source. At the instant t¢ when the source voltage is given by 
the current in the circuit will be
The given figure represents the phasor diagram of a series LCR circuit connected to an ac source. At the instant t¢ when the source voltage is given by the current in the circuit will be
physics-General
physics-
In a series CR circuit shown in figure, the applied voltage is 10 V and the voltage across capacitor is found to be 8V. Then the voltage across R, and the phase difference between current and the applied voltage will respectively be
In a series CR circuit shown in figure, the applied voltage is 10 V and the voltage across capacitor is found to be 8V. Then the voltage across R, and the phase difference between current and the applied voltage will respectively be
physics-General
physics-
In the circuit shown if the emf of source at an instant is 5 V, the potential difference across capacitor at the same instant is 4 V. The potential difference across R at that instant may be
In the circuit shown if the emf of source at an instant is 5 V, the potential difference across capacitor at the same instant is 4 V. The potential difference across R at that instant may be
physics-General
physics-
An inductive circuit contains resistance of 10 and an inductance of 2.0 H. If an AC voltage of 120 V and frequency 60 Hz is applied to this circuit, the current would be nearly:
An inductive circuit contains resistance of 10 and an inductance of 2.0 H. If an AC voltage of 120 V and frequency 60 Hz is applied to this circuit, the current would be nearly:
physics-General
physics-
In the circuit, as shown in the figure, if the value of R.M.S current is 2.2 ampere, the power factor of the box is
In the circuit, as shown in the figure, if the value of R.M.S current is 2.2 ampere, the power factor of the box is
physics-General
physics-
An ac-circuit having supply voltage E consists of a resistor of resistance 3 and an inductor of reactance 4 as shown in the figure. The voltage across the inductor at 
is
An ac-circuit having supply voltage E consists of a resistor of resistance 3 and an inductor of reactance 4 as shown in the figure. The voltage across the inductor at is
physics-General
physics-
The power factor of the circuit is 
The capacitance of the circuit is equal to
The power factor of the circuit is The capacitance of the circuit is equal to
physics-General
physics-
In the circuit shown in the figure, 
Switch S is closed at time t = 0. The current through and L would be equal after a time t equal to:
In the circuit shown in the figure, Switch S is closed at time t = 0. The current through and L would be equal after a time t equal to:
physics-General
