Current Electricity Mock Tests

A three-identical-resistor star (Y) configuration has equivalent resistance between any two terminals of:

A wire of resistance R is bent to form a closed circle. The effective resistance between two points diametrically opposite is:

A capacitor of capacitance C is charged through a resistor R from a battery of emf ε. At time t = τ = RC, the charge on the capacitor is q₁. If the charging continues until t = 2τ, the additional charge that flows through the circuit during the second time constant (from t = τ to t = 2τ) is:

In a meter bridge experiment, the null point is obtained at 40 cm from the left end when resistance R is in the left gap and 6 Ω is in the right gap. The value of R is:

A Wheatstone bridge has resistances P = 3 Ω, Q = 3 Ω in the two arms of the first pair, and R = 4 Ω in one arm of the second pair. The resistance S needed to balance the bridge is:

The drift velocity of electrons in a metallic wire will double if:

A battery of emf 12 V and internal resistance 2 Ω is connected to a resistor of 4 Ω. The potential difference across the resistor is:

A battery of emf 6 V and internal resistance 2 Ω is connected to a load resistance of 4 Ω. The power delivered to the load is: