Two conducting wires of the same material and of equal lengths and equal diameters are first connected in parallel and then in series in a circuit across the same potential difference. The ratio of heat produced in parallel and series combinations is

The magnetic field inside a long straight solenoid-carrying current

A car has an initial velocity of 12 m/s and is brought to rest over a distance of 45 m. The acceleration of the car is

The universal constant of gravitation G has the unit