Current Electri...

For comparing the electromotive force of two cells with a potentiometer, a standard cell is used to develop a potential gradient along the wire. Which of the following possibilities would make the experiment unsuccessful?

A circular coil of area $$8{m^2}$$  and number of turns 20 is placed in a magnetic field of 2T with its plane perpendicular to it. It is rotated with an angular velocity of 20rev/s about its natural axis. The emf induced is

Three resistances $$R_1,R_2$$ & $$R_3$$ $$(R_1> R_2> R_3)$$ are connected in series. If current $$I_1,I_2$$ & $$I_3$$ respectively is flowing through them, the correct relation will be

Eight resistances each of resistance $$5\Omega $$ are connected in the circuit as shown in figure. The equivalent resistance between $$A$$ and $$B$$ is

Two resistances of $$400\Omega$$ and $$800\Omega$$ are connected in series with a $$6$$ volt battery of negligible internal resistance. A voltmeter of resistance $$10,000\Omega$$ is used to measure the potential difference across $$400\Omega$$. The error in the measurement of the potential difference in volts approximately is :

If $${i_1} = 3\sin \omega t\,and\,{i_2} = 4\cos \omega t$$, then $$i_3$$ is

Two resistors $$R_1 \, (24 \pm 0.5) \Omega$$  and $$R_2 \, (8 \pm 0.3) \Omega$$ are joined in series. The equivalent resistance is 

The post office box works on the principle of :

Equivalence Resistance?

The inductance of a coil is $$L = 10 H$$ and resistance $$R = 5 \Omega$$. If applied voltage of battery is $$10 V$$ and it switches off in $$1$$ millisecond, find induced electromotive force of inductor.