Electric Energy, Power and Household Circuits — Physics STD 10 — Question

The unit for electric work in SI system:

A switch must be connected in :

Three identical cells of e.m.f. 4 V are connected in parallel. What is the combined e.m.f. of all?

Tick (✓) the correct choice among the following :
(a) A strong short bar magnet is dropped into a solenoid connected to a
galvanometer as shown in fig . The galvanometer shows a deflection to the left when the current in the coil as seen from above is counter clockwise. Which one of the following shows the correct deflection of the galvanometer when the magnet is at posi tions A, Band C.

For levers of first order, the mechanical advantage can have

The S1 unit of specific beat capacity is:

The rating of a fuse connected in the lighting circuit is :

A convex lens produces the image of the same size as the object when placed at a distance of 30 cm . Hence its focal length is:

The efficiency of an ideal machine is:

A ray of light incident on a lens parallel to its principal axis, after refraction passes through or appears to come from : ________ .