Physics Test 85

Some magnetic flux is changed from a coil of resistance 10 Ω. As a result an induced current is developed in it which varies with time as shown in figure. The magnitude of change in flux through the coil in weber is :

A long horizontal metallic rod with length along the east-west direction is falling under gravity. The potential difference between its two ends will :

Whenever a magnet is moved either toward or away from a conducting coil, an emf is induced. The magnitude of which is independent of

A 50 mH coil carries a current of 2 ampere. The energy stored in joules is :

The current passing through a choke coil of 5 henry is decreasing at the rate of 2 amp/sec. The emf developing across the coil is :

In a given circuit, the resistance R = 0.2 Ω. At a certain instant (V_A – V_B) = 0.5 volt, I = 0.5 Amp and (ΔI/Δt) = 8 A/s. Find the inductance of the coil :-

In the figure magnetic energy stored in the coil is :

The resistance and inductance of series circuit are 5Ω and 20H respectively. At the instant of closing the switch, the current is increasing at the rate 4 A/s, the supply voltage is :

A straight wire of length L is bent into a semicircle. It is moved in a uniform magnetic field with speed v with a diameter perpendicular to field. The induce emf between. The ends of wire is :

A rectangular loop of sides a and b is placed in x-y plane. A uniform but time varying magnetic field of strength  is present in the region. The magnitude of induced emf in the loop at time t is :