QUES: Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotlight is more intense than the light from a domestic lightbulb; that is to say that the spotlight gives out more energy per unit time and per unit space(and hence consumes more electricity) than the ordinary bulb, even though the colour of the light might be very similar. Other waves, such as sound or the waves crashing against a seafront, also have their own intensity. However, the energy account of the photoelectric effect didn't seem to agree with the wave description of light.

What does it mean for a light source to be more intense than another?
What is the answer?
ANS: gives out more energy per unit time and per unit space
QUES: The city is home to 261,546 (mid-2014 est.) people, making it the 30th most populous built-up area in the United Kingdom. It is governed locally by Plymouth City Council and is represented nationally by three MPs. Plymouth's economy remains strongly influenced by shipbuilding and seafaring including ferry links to Brittany (Roscoff and St Malo) and Spain (Santander), but has tended toward a service-based economy since the 1990s. It has the largest operational naval base in Western Europe – HMNB Devonport and is home to Plymouth University.

How many members of Parliament represent Plymouth?
What is the answer?
ANS: three
QUES: The vast majority of devices containing LEDs are "safe under all conditions of normal use", and so are classified as "Class 1 LED product"/"LED Klasse 1". At present, only a few LEDs—extremely bright LEDs that also have a tightly focused viewing angle of 8° or less—could, in theory, cause temporary blindness, and so are classified as "Class 2". The opinion of the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) of 2010, on the health issues concerning LEDs, suggested banning public use of lamps which were in the moderate Risk Group 2, especially those with a high blue component in places frequented by children. In general, laser safety regulations—and the "Class 1", "Class 2", etc. system—also apply to LEDs.

 What does being a Class 2 LED product mean?
What is the answer?
ANS:
unanswerable