List of top Physics Questions asked in JEE Main

The space inside a straight current carrying solenoid is filled with a magnetic material having magnetic susceptibility equal to \(1.2 \times 10^{–5}\). What is fractional increase in the magnetic field inside solenoid with respect to air as medium inside the solenoid?
Two parallel, long wires are kept 0.20 m apart in vacuum, each carrying current of x A in the same direction. If the force of attraction per meter of each wire is \(2 \times 10^{–6} \text{N}\), then the value of x is approximately:
At a certain place the angle of dip is 30° and the horizontal component of earth’s magnetic field is 0.5 G. The earth’s total magnetic field (in G), at that certain place, is
BX and BY are the magnetic field at the centre of two coils X and Y, respectively each carrying equal current. If coil X has 200 turns and 20 cm radius and coil Y has 400 turns and 20 cm radius, the ratio of BX and BY is
A circular coil of \(1000\) turns each with area \(1\ m^2\) is rotated about its vertical diameter at the rate of one revolution per second in a uniform horizontal magnetic field of \(0.07\ T\). The maximum voltage generation will be _____ V.
A triangular shaped wire carrying 10 A current is placed in a uniform magnetic field of 0.5 T, as shown in figure. The magnetic force on segment CD is (Given BC = CD = BD = 5 cm).
uniform magnetic field
The magnetic field at the center of current carrying circular loop is \(B_1\). The magnetic field at a distance of √3 times radius of the given circular loop from the center on its axis is \(B_2\). The value of \(B_1/B_2\) will be
A metallic rod of length \(20\) cm is placed in North-South direction and is moved at a constant speed of 20 m/s towards East. The horizontal component of the Earth’s magnetic field at that place is \(4 × 10^{–3}\) T and the angle of dip is \(45º\). The emf induced in the rod is __________mV.
The space inside a straight current carrying solenoid is filled with a magnetic material having magnetic susceptibility equal to 1.2 × 10–5. What is fractional increase in the magnetic field inside solenoid with respect to air as medium inside the solenoid?
The vertical component of the earth’s magnetic field is 6 × 10–5 T at any place where the angle of dip is 37°. The earth’s resultant magnetic field at that place will be (Given tan 37° = ¾)
The equation of current in a purely inductive circuit is $5 \sin \left(49 \pi t -30^{\circ}\right)$ If the inductance is $30\, mH$ then the equation for the voltage across the inductor, will be: $\left\{\text { Let } \pi=\frac{22}{7}\right\}$
Match List-I with List-II
List-IList-II
(A) AC generator(I) Detects the presence of current in the circuit
(B) Galvanometer(II) Converts mechanical energy into electrical energy
(C) Transformer(III) Works on the principle of resonance in AC circuit
(D) Metal detector(IV) Changes an alternating voltage for smaller or greater value
Choose the correct answer from the options given below.
If wattless current flows in the AC circuit, then the circuit is:

In the circuit, the logical value of A = 1 or B = 1 when potential at A or B is 5 V and the logical value of A = 0 or B = 0 when potential at A or B is 0 V. The truth table of the given circuit will be:

 

In a series \(LR\) circuit \(X_L=R\) and power factor of the circuit is \(P_1\). When capacitor with capacitance C such that \(X_L=X_C\) is put in series, the power factor becomes \(P_2\). The ratio \(\frac {P_1}{P_2}\) is

An AC source is connected to an inductance of 100 mH, a capacitance of 100 μF and a resistance of 120 Ω as shown in the figure. The time in which the resistance having a thermal capacity 2 J/°C will get heated by 16°C is ___ s.
 

Fig. Circuit

A telegraph line of length 100km has a capacity of 0.01μF/km, and it carries an alternating current at 0.5kilo cycle per second. If the minimum impedance is required, then the value of the inductance that needs to be introduced in series is ______ mH.
(if π = √10)

A transformer operating at primary voltage 8 kV and secondary voltage 160 V serves a load of 80 kW. Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the loads in the primary and secondary circuit would be

A series LCR circuit has
\(L = 0.01H, R = 10Ω\ and\ C = 1µF\)
and it is connected to ac voltage of amplitude (Vm)50 V. At frequency 60% lower than resonant frequency, the amplitude of current will be approximately

To light, a W, 100 V lamp is connected, in series with a capacitor of capacitance 
\(\frac{50}{π\sqrt{x}}\mu F\) with \(200 V\), 50 Hz AC source.
The value of x will be ___.

In the given circuit, the magnitude of VL and VC are twice that of VR. Given that f = 50 Hz, the inductance of the coil is 1/(Kπ) mH. The value of K is ________.

Fig.
Two metallic wires of identical dimensions are connected in series. If σ1 and σ2 are the conductivities of these wires, respectively, the effective conductivity of the combination is :
An alternating emf \(E = 440 \sin(100\pi t)\) is applied to a circuit containing an inductance of \(\frac{\sqrt{2}}{\pi}\) H. If an a.c. ammeter is connected in the circuit, its reading will be:
An alternating emf \(E = 440 \sin(100\pi t)\) is applied to a circuit containing an inductance of \(\frac{\sqrt{2}}{\pi}\) H. If an a.c. ammeter is connected in the circuit, its reading will be:
The current \(I\) flowing through the given circuit will be ________A.
current flowing through the circuit