A cell sends a current through a resistance $R$ for time $t.$ Now the same cell sends current through another resistance $r$ for the same time. If same amount of heat is developed in both the resistance, then the internal resistance of cell is

According to this diagram, the potential difference across the terminals is (internal resistance of cell $=r)$

Reading of an ideal voltmeter in the circuit below is

The value of current through $2\mathrm{\Omega }$ resistor is

The reading of the ammeter in the circuit below is

The ammeter reading in the circuit below is