Find the energy stored in a 120 cm length of a laser beam operating at 6 mW.

A parallel plate capacitor of capacitance C is charged to a potential V. It is then connected to another uncharged capacitor having the same capacitance. Find out the ratio of the energy stored in the combined system to that stored initially in the single capacitor.

Find the length of an arc of circle of radius 6cm subtending an angle of 15^(@) at the centre.

In a circle of diameter 40 cm, the length of a chord is 20 cm. Find the length of minor arc of the chord.

Suppose the initial charge on the capacitor in Exercise 7.7 is 6mC. What is the total energy stored in the circuit initially? What is the total energy at later time?

Monochromatic light of wavelength 632.8 nm is produced by a helium-neon laser. The power emitted is 9.42 mW. Find the energy and momentum of each photon in the light beams.

A capacitor of capacitance 6muF is charged by a 6V battery. The charged capacitor is now connected to an indcutor of inductance 2 mH. Find the current I the circuit, when one-third energy stored in the capacitor converts into the energy stored in the inductor.

Find the lateral surface and total surface area of a cuboid of length 80 cm, breadth 40 cm and height 20 cm.

The sum of the length breadth and height of the cuboid is 16 cm and the length of its diagonal is 12 cm. find the total surface area of the cuboid.