Define Isobar.

Define Isobar.

• A. Lines of equal temperature.
• B. Equal lines of pressure in millibars = strong pressure gradient = faster winds.
• C. Lines representing temperature variation across a map.
• D. Imaginary lines connecting points of equal humidity.

Answer: (B)

Isobar means a line on a weather map that connects points of equal atmospheric pressure, usually at mean sea level, and is drawn using pressure values in millibars (hPa). This definition is why the correct answer emphasizes equal lines of pressure in millibars and notes that a strong pressure gradient—when these lines are close together—produces faster winds. The idea behind wind speed is the pressure gradient force: the steeper the gradient (closer isobars), the stronger the wind. Other options describe lines of equal temperature (isotherms) or lines related to humidity, which are not what isobars represent. This is why they don’t fit as definitions of an isobar.

Isobar means a line on a weather map that connects points of equal atmospheric pressure, usually at mean sea level, and is drawn using pressure values in millibars (hPa). This definition is why the correct answer emphasizes equal lines of pressure in millibars and notes that a strong pressure gradient—when these lines are close together—produces faster winds. The idea behind wind speed is the pressure gradient force: the steeper the gradient (closer isobars), the stronger the wind.

Other options describe lines of equal temperature (isotherms) or lines related to humidity, which are not what isobars represent. This is why they don’t fit as definitions of an isobar.