Physics Past Questions and Answers

It takes 4 minutes to boil a quantity of water electrically. How long will it take to boil same quantity of water using the same heating coil but with the current doubled? (neglecting any external heat loss).

A 64 minutes
B 32 minutes
C 8 minutes
D 2 minutes
E 1 minute

Question 57:

A lamp is marked 220V 60 W. Calculate the energy it would consume when connected to a 220V source for 1 hour.

A 216000J
B 13200J
C 3600J
D 864J
E 220J

Question 58:

What is the effect of using split-rings in a simple d.c motor?

A The direction of rotation of the coil is reversed
B The current in the coil flows in the same direction
C The current in the coil becomes alternating
D The direction of the force on the coil is reversed
E The contact with the voltage is cut-off

Question 59:

Which of the following statement is not correct about loaded spiral spring?

A The extension is proportional to the load applied, provided the elastic limite is not exceeded
B If the elsatic limit is not exceeded, the contraction is proportional to the load removed.
C Up to the yield limit, extension is no longer proportional to the applied load.
D Beyond the elsatic limit, extension is no longer proportional to the applied load.
E If the string regains its shape or form after deformation, it is said to be elastic.

Question 60:

B 0.006Ωcm
C 0.26700Î©cm
D 0.27500Î©cm
E 0.060000Î©cm