A converging lens of focal length 5cm forms a virtual image which is 20cm from the lens. How far from the lens is the object?

In an operating X-ray tube, a high p.d is applied between the cathode and the anode for the purpose of

An object 8cm in front of a plane mirror moves at a speed of 6cm s-1 away from the mirror. What will be the distance separating the object and the image afte...

Which colour is deviated least when white light passes through a triangular prism?

The energy stored in a capacitor of capacitance 5 μF is 40J. What is the voltage applied across its terminals?

Which is a fundamental unit?

The ability of the eye to focus on objects at various distances is known as

An electric heater takes 4A when operated on a 250V supply. What is the cost of the electricity consumed at 10k per kWh when the heater is used for 5 hours?

Which device does NOT make use of the magnetic effects of an electric current?