A working electric motor takes a current of 1.5 A when the p.d across it is 250V. If its efficiency is 80%, the power output is

• A. 300.0W
• B. 469.0W
• C. 133.0W
• D. 4.8W

In order to remove the error of parallax when taking measurements with a metre rule, the eye should be focused

• A. slantingly towards the right on the markings
• B. slantingly towards the left on the markings
• C. vertically downwards on the markings
• D. vertically upwards on the markings

The melting point of naphthalene is 78^oC. What is this temperature in kelvin

• A. 100k
• B. 351k
• C. 378k
• D. 444k

The refractive index of a material is 1.5. Calculate the critical angle at the glass-air interface

• A. 19^o
• B. 21^o
• C. 39^o
• D. 42^o

The magnitude of the force experienced by a charge of 1.6 x 10\(^{-8}\)C in a uniform electric field of intensity 5 x 105NC\(^{-1}\) is

• A. 3.2 x 10\(^{-14}\)N
• B. 8.0 x 10\(^{-13}\)N
• C. 8.0 x 10\(^{-3}\)N
• D. 3.1 x 10\(^{13}\) N

In the diagram below, if the south-poles of two magnets strokes steel bar, the polarities at T and V will respectively be

• A) south and north
• B) north and south
• C) north and north
• D) south and south

(a) Define electrolysis.

(b) Classify each of the following substances as an electrolyte or a non-electrolyte

(i) sugar solution;

(ii) kerosene;

(iii) alkaline solution

(iv) lemon fruit juice.

An astronomical telescope is said to be in normal adjustment when the

• A. eye is accommodated
• B. focal length of objective lens is longer than that of eye piece
• C. final image is at the near point of eye
• D. final image is at infinity

The pressure applied to an enclosed fluid to one end id transmitted equally throughout the fluid and to the container walls. This statement is

• A. Archimede's principle
• B. Bernoulli's principle
• C. Pascal's principle Heisenberg's
• D. Heisenberg's uncertainty principle

The velocity v, of a wave in a stretched string, depends on the tension T, in the spring and the mass per unit length of the spring. Obtain an expression for v in terms of T and u, using the method of dimensions.