Heat Transfer PHYSICS - Heat Transfer

• A
  Iron rims are cooled before they are placed on the cart wheels.
• B
  A glass stopper gets tighten on warming the neck of the bottle.
• C
  Telephone wires sag in winter but become tight in summer.
• ✓
  A little space is left between two rails on a railway track.

Answer: D.

• A
  the initial length of the rod only
• B
  the rise in temperature only
• C
  the material of rod only
• ✓
  all the above three factors.

Answer: D.

• A
  alcohol contracts, but water expands
• B
  water contracts, but alcohol expands
• C
  water expands more than alcohol
• ✓
  alcohol expands more than water.

Answer: D.

• A
  the solid  rod $ A$ expands more than the hollow rod $ B$
• B
  the hollow rod $B$ expands more than the solid rod $A$
• C
  the hollow rod $B$ contracts, but the solid rod $A$ expands
• ✓
  both the rods $A$ and $B$ expand the same.

Answer: D.

• A
  both the rods $A$ and $B$ elongate the same
• B
  the rod $A$ elongates more than the rod $B$
• ✓
  the rod $B$ elongates more than the rod $ A$
• D
  the rod $A$ elongates, but the rod $B$ contracts.

Answer: C.