The image formed by a concave lens is always MCQ with Answer and Explanation

Explanation:
kWh used for billing.

Explanation:
Galvanometer is sensitive instrument for detecting presence and direction of small currents. Ammeter measures larger currents. Voltmeter potential difference. Wattmeter power.

Explanation:
Electric potential V at a point is defined as work done per unit charge to bring a test charge from infinity to that point: V = W/q. Thus potential difference between two points is work per unit charge to move between them. Electric field intensity is force per unit charge; potential energy is work to assemble charges; capacitance is charge storage ability. Memory tip: 'Potential = work per unit charge; field = force per unit charge'. This definition-based question tests electrostatics fundamentals, frequently appearing in competitive exams. Always distinguish potential (scalar, work/charge) from field (vector, force/charge).