Out of the following metals A, B and C of specific heat capacities 900 J kg⁻¹ °C⁻¹, 380 J kg⁻¹ °C⁻¹ and 460 J kg⁻¹ °C⁻¹ respectively, which one will you prefer for calorimeter? Give reason.

State condition in each case for the magnitude of force on a current carrying conductor placed in a magnetic field to be (a) zero, (b) maximum

The figure given below shows a radioactive nucleus A composed of 84 protons and 128 neutrons kept in a thick lead walled container. The emitted particles pass through a magnetic field in a direction perpendicular to the plane of paper inwards as shown by X. The nucleus A emits a particle which deflects to the left and is transformed into nucleus B. Nucleus B further emits a particle which deflects towards right and transforms into nucleus C.

(a) Name the radiations emitted by nucleus A and B.

(b) Name the law used to identify the radiations.

(c) What is the composition of nucleus C?

Jatin puts a pencil into a glass container having water and is surprised to see the pencil in a different state.

(a) What change is observed in the appearance of the pencil?

(b) What is the reason for this change?

(c) Classify the following as a real or virtual image:
The image of a candle flame formed on a screen by a convex lens.