Hydraulic brakes used in automobiles operate on the basis of: MCQ with Answer and Explanation

Explanation:
Photovoltaic effect: photons excite electrons in semiconductor, creating voltage. Direct light-to-electricity conversion. Memory tip: 'Photo = light; voltaic = electricity'. Renewable energy principle frequently tested in competitive exams to assess energy conversion understanding.

Explanation:
Torque τ = r × F, so dimensions [L][MLT⁻²] = [ML²T⁻²]. Work W = F·d, dimensions [MLT⁻²][L] = [ML²T⁻²], identical. Momentum is [MLT⁻¹], force [MLT⁻²], power [ML²T⁻³]. Though torque and work have same dimensions, they are physically distinct: torque is vector (rotational effect), work is scalar (energy transfer). Memory tip: 'Torque and work share [ML²T⁻²]; but torque = rF sinθ, work = Fd cosθ'. This dimensional analysis question tests ability to compare quantities, frequently appearing in competitive exams. Always verify dimensions but remember physical context differs.

Explanation:
Load between fulcrum and effort: nutcracker, wheelbarrow. Scissors first order, fishing rod third.