Question

why does aa bulb does not glow in a circuit whose wires are connected to the same terminals of a cell?

Answer 1

Bulb glows when current flows through the circuit and the current flows (from positive terminal to negative terminal) when electrons flows from negative terminal of the battery to the its positive terminal. So, when a wire of the circuit is connected to the same terminal of the cell then no flow of electron or current will take place in the circuit or we may say that circuit does not act as a closed circuit. As a result the bulb will not glow.