Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

The increase in the speed of a car is proportional to the additional petrol put into the engine. Is it possible to accelerate a car without putting more petrol or less petrol into the engine?

To observe the photoelectric effect, the frequency of incident light should be greater than which frequency?

A biconvex lens made of a transparent material of refractive index 1.25 is immersed in water of refractive index 1.33. Will the lens behave as a converging or a diverging lens? Give reason.

Does the magnifying power of a microscope depend on the colour of the light used? Justify your answer.

Can you, have an AG series circuit in which there is. a phase difference of 180° between the emf and the current? 120°?

Is a vector necessarily changed if it is rotated through an angle?

Can alternating galvanometer measure both alternating and direct currents?

What is the importance of Gaussian surface?

Can the earth's magnetic field be vertical at a place? What will happen to a lreely suspended magnet at such a place? What is the value of dip here?