NECO Physics Past Questions & Answers - Page 44

216.

A body is uniformly accelerated from rest. Which of the following quantities vary/varies linearly with the square of the time?

I. Displacement
II. Velocity
III. Momentum

A.

I only

B.

II only

C.

III only

D.

I and II only

E.

II and Ill only

Correct answer is A

No explanation has been provided for this answer.

218.

When a current of 1 .0A flows in an electrolyte for 3.0h, a mass of 1 .0g is deposited. What mass will be deposited in 10.0h if a current of 3.0A flows through the electrolyte?

A.

30.0g

B.

24.0g

C.

10.0g

D.

6.0g

E.

0.4g

Correct answer is C

Q = charge
i = current
t = time in sec

Mass(M1)
3hours to sec
60*60*3= 10800
Mass(M2)

10hours to sec
60*60*10 = 36,000
36,000 * 3.0A = 108,000

if it takes 10800 current to discharge 1g
how much will it take 108000

10800---->1
108000---x

= 108000/10800

=10

219.

Which process will increase the rate of oscillation of a pendulum?

A.

decreasing the amplitude of oscillation of the pendulum

B.

decreasing the length of the pendulum

C.

decreasing the mass of the pendulum

D.

increasing the length of the pendulum

E.

increasing the mass of the pendulum.

Correct answer is B

No explanation has been provided for this answer.

220.

Lenz’s law of electromagnetic induction states that

A.

e.m.f. is induced in a circuit whenever there is a change in the magnetic flux linked with the circuit

B.

the induced e.m.f. in a circuit is proportional to the rate of change f the number of lines of force linking the circuit

C.

the induced current in a conductor is in such a direction as to oppose the change producing it

D.

a force is exerted in a current-carrying conductor in a magnetic field.

E.

the induced e.m.f. is proportional to the current producing the magnetic flux.

Correct answer is C

No explanation has been provided for this answer.